Apparatus and method to support ultra-wide bandwidth in fifth generation (5G) new radio

ABSTRACT

A method of a communication technique in which a fifth generation (5G) communication system for supporting more high data transmission rate after a fourth generation (4G) system converges with an internet of things (IoT) technology, and a system is provided. The present disclosure may be applied to intelligent services (e.g., a smart home, a smart building, a smart city, a smart car or a connected car, healthcare, digital education, a retail business, security and safety-related services, or the like) based on a 5G communication technology and an IoT-related technology. A terminal receives, from a base station, a first message including configuration information of at least one band, receive, from the base station, a second message for activating a band among the at least one band, and activate the band according to the second message, the configuration information including indication of the at least one band, and each band of the at least one band being part of a bandwidth.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a continuation of prior application Ser. No.17/105,873 filed on Nov. 27, 2020, which will be issued as U.S. Pat. No.11,564,151 on Jan. 24, 2023; which is a continuation of priorapplication Ser. No. 16/678,346 filed on Nov. 8, 2019, which has issuedas U.S. Pat. No. 10,863,421 on Dec. 8, 2020; which is a continuationapplication of prior application Ser. No. 15/799,001 filed on Oct. 31,2017, which has issued as U.S. Pat. No. 10,477,457, on Nov. 12, 2019;and which claimed the benefit under 35 U.S.C. § 119(a) of a Koreanpatent application filed on Nov. 3, 2016 in the Korean IntellectualProperty Office and assigned Serial number 10-2016-0146078, and under 35U.S.C. § 119(a) of a Korean patent application filed on Mar. 23, 2017 inthe Korean Intellectual Property Office and assigned Serial number10-2017-0037164, and under 35 U.S.C. § 119(a) of a Korean patentapplication filed on Jun. 15, 2017 in the Korean Intellectual PropertyOffice and assigned Serial number 10-2017-0076096 and under 35 U.S.C. §119(a) of a Korean patent application filed on Aug. 10, 2017 in theKorean Intellectual Property Office and assigned Serial number10-2017-0101930, and under 35 U.S.C. § 119(a) of a Korean patentapplication filed on Oct. 31, 2017 in the Korean Intellectual PropertyOffice and assigned Serial number 10-2017-0144091, the entire disclosureof each of which is hereby incorporated by reference.

TECHNICAL FIELD

The present disclosure relates to a physical layer (PHY)/medium accesscontrol (MAC) layer operation of a terminal and a base station in amobile communication system. More specifically, the present disclosurerelates to a method and an apparatus capable of efficiently using abandwidth and flexibly and dynamically supporting a bandwidth changebecause signal transmission/reception may be achieved only in a limitedbandwidth due to a limited operating bandwidth and power consumption ofa terminal when a base station tries to transmit/receive an ultra-widebandwidth signal to/from a single carrier.

BACKGROUND

To meet a demand for radio data traffic that is on an increasing trendsince commercialization of a fourth generation (4G) communicationsystem, efforts to develop an improved fifth generation (5G)communication system or a pre-5G communication system have beenconducted. For this reason, the 5G communication system or the pre-5Gcommunication system is called a beyond 4G network communication systemor a post long term evolution (LTE) system. To achieve a high datatransmission rate, the 5G communication system is considered to beimplemented in a very high frequency (mmWave) band (e.g., like 60 GHzband). To relieve a path loss of a radio wave and increase a transferdistance of the radio wave in the very high frequency band, in the 5Gcommunication system, beamforming, massive MIMO, full dimensional MIMO(FD-MIMO), array antenna, analog beam-forming, and large scale antennatechnologies have been discussed. Further, to improve a network of thesystem, in the 5G communication system, technologies, such as an evolvedsmall cell, an advanced small cell, a cloud radio access network (cloudRAN), an ultra-dense network, a device to device communication (D2D), awireless backhaul, a moving network, cooperative communication,coordinated multi-points (CoMP), and reception interference cancellationhave been developed. In addition to this, in the 5G system, hybrid FSKand QAM modulation (FQAM) and sliding window superposition coding (SWSC)that are an advanced coding modulation (ACM) scheme and a filter bankmulti carrier (FBMC), a non orthogonal multiple access (NOMA), and asparse code multiple access (SCMA) that are an advanced accesstechnology, and so on have been developed.

Meanwhile, the Internet is evolved from a human-centered connectionnetwork through which a human being generates and consumes informationto the internet of things (IoT) network that transmits/receivesinformation between distributed components, such as things and processesthe information. The internet of everything (IoE) technology in whichthe big data processing technology, and the like, is combined with theIoT technology by connection with a cloud server, and the like, has alsoemerged. To implement the IoT, technology elements, such as a sensingtechnology, wired and wireless communication and network infrastructure,a service interface technology, and a security technology, have beenrequired. Recently, technologies, such as a sensor network, machine tomachine (M2M), and machine type communication (MTC) for connectingbetween things have been researched. In the IoT environment, anintelligent internet technology (IT) service that creates a new value inhuman life by collecting and analyzing data generated in the connectedthings may be provided. The IoT may apply for fields, such as a smarthome, a smart building, a smart city, a smart car or a connected car, asmart grid, health care, smart appliances, and an advanced healthcareservice, by fusing and combining the existing information technology(IT) with various industries.

Therefore, various tries to apply the 5G communication system to the IoTnetwork have been conducted. For example, the 5G communicationtechnologies, such as the sensor network, the M2M, and the MTC, havebeen implemented by techniques, such as the beamforming, the MIMO, andthe array antenna. The application of the cloud radio access network(cloud RAN) as the big data processing technology described above mayalso be considered as an example of the fusing of the 5G communicationtechnology with the IoT technology.

The existing LTE system has adopted a multi-carrier scheme in whichmultiple component carriers (CCs), such as carrier aggregation (CA) anddual connectivity (DC) are bundled and operated to support a wideband.Aggregating up to 32 CCs may support a bandwidth of 640 MHz on a 20 MHzCC basis. However, if a scheme, such as LTE CA is applied to supportultra-wide bandwidth, for example, 1 GHz in a 5G new radio (NR) system,the number of combinations of CCs to be used by the terminal isincreased exponentially, a size of a UE-capability report is increased,and the 5G NR system cannot but operate only within the limited numberof combinations of CCs. In addition, as the number of CCs is increasedin the CA, reception complexity of the terminal and control complexityof the base station are increased together. However, despite theseproblems of the CA/DC, the CA/DC shows higher flexibility in resourceusage than single carrier. This is because an extension bandwidth may bechanged by addition/release of a secondary cell (SCell), and thetransmission/reception of resources to another CC may be scheduled bycross-carrier scheduling.

The above information is presented as background information only toassist with an understanding of the present disclosure. No determinationhas been made, and no assertion is made, as to whether any of the abovemight be applicable as prior art with regard to the present disclosure.

SUMMARY

Aspects of the present disclosure are to address at least theabove-mentioned problems and/or disadvantages and to provide at leastthe advantages described below. Accordingly, an aspect of the presentdisclosure is to provide a limited signal transmission/receptionprocedure of a base station and a terminal based on power consumption ofthe terminal in a single carrier and a controlling method capable ofdynamically and flexibly using the whole bandwidth of a system.

Another aspect of the present disclosure is not limited to theabove-mentioned aspect. For example, other objects that are notmentioned may be obviously understood by those skilled in the art towhich the present disclosure pertains from the following description.

In accordance with an aspect of the present disclosure, a communicationmethod of a terminal is provided. The method includes receiving, from abase station, a first message comprising configuration information of atleast one band, receiving, from the base station, a second message foractivating a band among the at least one band, and activating the bandaccording to the second message, wherein the configuration informationcomprises indication of the at least one band, and wherein each band ofthe at least one band is part of a bandwidth.

In the method, the configuration information comprises at least one ofnumerology information, frequency location information of the at leastone band, and number of resource block of the at least one band.

In the method, the second message comprises downlink at least one ofdownlink control information (DCI).

In the method, the configuration information of at least one bandcomprises at least one of configuration information of at least onedownlink band and configuration information of at least one uplink band.

In the method, the configuration information of the at least onedownlink band comprises at least one of resource information of at leastone control region with user equipment (UE)-specific search space andresource information of a control region with common search space.

In the method, the configuration information of the at least one uplinkband comprises resource information of at least one UE-specific controlregion.

In the method, the activating comprises: receiving, from the basestation, control information in the band, and receiving, from the basestation, downlink signal in the band no later than a predetermined timeafter receiving the control information.

In accordance with another aspect of the present disclosure, acommunication method of a base station is provided. The method includestransmitting, to a terminal, a first message comprising configurationinformation of at least one band, and transmitting, to the terminal, asecond message for activating a band among the at least one band,wherein the configuration information comprises indication of the atleast one band, and wherein each band of the at least one band is partof a bandwidth.

In the method, the configuration information comprises at least one ofnumerology information, frequency location information of the at leastone band, and number of resource block of the at least one band.

In the method, the second message comprises at least one of DCI.

In the method, the configuration information of at least one bandcomprises at least one of configuration information of at least onedownlink band and configuration information of at least one uplink band.

In the method, the configuration information of the at least onedownlink band comprises at least one of resource information of at leastone control region with UE-specific search space and resourceinformation of a control region with common search space.

In the method, the configuration information of the at least one uplinkband comprises resource information of at least one UE-specific controlregion.

In the method, further comprises transmitting, to the terminal, controlinformation in the band, and transmitting, to the terminal, downlinksignal in the band no later than a predetermined time after transmittingthe control information.

In accordance with another aspect of the present disclosure, a terminalis provided. The terminal includes a transceiver configured to transmitand receive signals, and a controller configured to receive, from a basestation, a first message comprising configuration information of atleast one band, receive, from the base station, a second message foractivating a band among the at least one band, and activate the bandaccording to the second message, wherein the configuration informationcomprises indication of the at least one band, and wherein each band ofthe at least one band is part of a bandwidth.

In accordance with another aspect of the present disclosure, a basestation is provided. The base station includes a transceiver configuredto transmit and receive signals, and a controller configured totransmit, to a terminal, a first message comprising configurationinformation of at least one band, and transmit, to the terminal, asecond message for activating a band among the at least one band,wherein the configuration information comprises indication of the atleast one band, and wherein each band of the at least one band is partof a bandwidth.

According to an embodiment of the present disclosure, a plurality ofterminals having various sizes of bands may be controlled to useresources evenly in the operating bandwidth of the system. In addition,the terminal can perform the scheduling, the modulation and codingscheme (MCS), the channel state indication (CSI) report, themeasurement, and the like within the configured partial bands, and thereduction in scheduling and handover performance for the whole bandwidthmay be minimized. In addition, if the terminal causes the connectionproblem within the configured partial bands, it is possible to recoverthe connection within a short delay.

The effects that may be achieved by the embodiments of the presentdisclosure are not limited to the above-mentioned objects. For example,other effects that are not mentioned may be obviously understood bythose skilled in the art to which the present disclosure pertains fromthe following description.

Other aspects, advantages, and salient features of the disclosure willbecome apparent to those skilled in the art from the following detaileddescription, which, taken in conjunction with the annexed drawings,discloses various embodiments of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features, and advantages of certainembodiments of the present disclosure will be more apparent from thefollowing description taken in conjunction with the accompanyingdrawings, in which:

FIG. 1 is a diagram illustrating a scalable bandwidth (BW) system oflong term evolution (LTE) according to various embodiments of thepresent disclosure;

FIG. 2 is a diagram illustrating various band partitioning schemesaccording to various embodiments of the present disclosure;

FIG. 3 is a diagram of a band partitioning structure according to anembodiment of the present disclosure;

FIG. 4A is a diagram illustrating an operating downlink datatransmission/reception scheduling and uplink data transmission/receptionscheduling according to an embodiment of the present disclosure;

FIG. 4B is a diagram illustrating a downlink data scheduling schemeaccording to an embodiment of the present disclosure;

FIG. 5 is a diagram illustrating a relationship between hybridautomatic-repeat-request (HARQ) and a band according to an embodiment ofthe present disclosure;

FIG. 6 is a diagram illustrating a first operation of transmitting acommon signal from a higher layer to a terminal according to anembodiment of the present disclosure;

FIG. 7 is a diagram illustrating a second operation of transmitting acommon signal from a higher layer to a terminal according to anembodiment of the present disclosure;

FIG. 8 is a diagram illustrating a third operation of transmitting acommon signal from a higher layer to a terminal according to anembodiment of the present disclosure;

FIG. 9 is a diagram illustrating a fourth operation of transmitting acommon signal from a higher layer to a terminal according to anembodiment of the present disclosure;

FIG. 10 is a diagram illustrating control sub-band structures accordingto an embodiment of the present disclosure;

FIG. 11 is a diagram illustrating a band recovery procedure according toan embodiment of the present disclosure;

FIG. 12 is a diagram illustrating a band recovery procedure according toan embodiment of the present disclosure;

FIG. 13 is a diagram illustrating a band recovery procedure according toan embodiment of the present disclosure;

FIG. 14 is a diagram illustrating a band recovery procedure according toan embodiment of the present disclosure;

FIG. 15 is a diagram illustrating a monitoring bandwidth of a terminalfor a serving base station and a neighboring base station according toan embodiment of the present disclosure;

FIG. 16 is a diagram illustrating a monitoring bandwidth of a terminalfor a serving base station and a neighboring base station according toan embodiment of the present disclosure;

FIG. 17 is a diagram illustrating a monitoring bandwidth of a terminalfor a serving base station and a neighboring base station according toan embodiment of the present disclosure;

FIG. 18 is a diagram illustrating a monitoring bandwidth of a terminalfor a serving base station and a neighboring base station according toan embodiment of the present disclosure;

FIG. 19 is a diagram illustrating a flexible bandwidth (BW) systemdesired in a fifth generation (5G) communication system according to anembodiment of the present disclosure;

FIG. 20 is a diagram illustrating a configuration of a terminalaccording to an embodiment of the present disclosure;

FIG. 21 is a diagram illustrating a configuration of a base stationaccording to an embodiment of the present disclosure.

Throughout the drawings, it should be noted that like reference numbersare used to depict the same or similar elements, features, andstructures.

DETAILED DESCRIPTION

The following description with reference to the accompanying drawings isprovided to assist in a comprehensive understanding of variousembodiments of the present disclosure as defined by the claims and theirequivalents. It includes various specific details to assist in thatunderstanding but these are to be regarded as merely exemplary.Accordingly, those of ordinary skill in the art will recognize thatvarious changes and modifications of the various embodiments describedherein can be made without departing from the scope and spirit of thepresent disclosure. In addition, descriptions of well-known functionsand constructions may be omitted for clarity and conciseness.

The terms and words used in the following description and claims are notlimited to the bibliographical meanings, but, are merely used by theinventor to enable a clear and consistent understanding of the presentdisclosure. Accordingly, it should be apparent to those skilled in theart that the following description of various embodiments of the presentdisclosure is provided for illustration purpose only and not for thepurpose of limiting the present disclosure as defined by the appendedclaims and their equivalents.

It is to be understood that the singular forms “a,” “an,” and “the”include plural referents unless the context clearly dictates otherwise.Thus, for example, reference to “a component surface” includes referenceto one or more of such surfaces.

By the term “substantially” it is meant that the recited characteristic,parameter, or value need not be achieved exactly, but that deviations orvariations, including for example, tolerances, measurement error,measurement accuracy limitations and other factors known to those ofskill in the art, may occur in amounts that do not preclude the effectthe characteristic was intended to provide.

It is to be understood that when one component is referred to as being“connected to” or “coupled to” another component in the presentspecification, it may mean that one component is connected directly toor coupled directly to another component or electrically connected to orcoupled to another component with the other component interposed therebetween. Further, in the present specification, “comprising” a specificconfiguration will be understood that additional configuration may alsobe included in the embodiments or the scope of the technical idea of thepresent disclosure.

Furthermore, constitutional parts shown in the embodiments of thepresent disclosure are independently shown so as to represent differentcharacteristic functions. Thus, it does not mean that eachconstitutional part is constituted in a constitutional unit of separatedhardware or one software. For example, for convenience of description,the respective constitutional parts are included by being arranged aseach constitutional part and at least two constitutional parts of therespective constitutional parts may form one constitutional part or oneconstitutional part is divided into a plurality of constitutional partsto perform functions. An integrated embodiments and a separatedembodiment of the respective constitutional parts are also included inthe scope of the present disclosure unless departing from the nature ofthe present disclosure.

In addition, some of constituents may not be indispensable constituentsperforming essential functions of the present disclosure but beselective constituents improving only performance thereof. The presentdisclosure may be implemented by including only the indispensableconstitutional parts for implementing the essence of the presentdisclosure except the constituents used in improving performance. Thestructure including only the indispensable constituents except theselective constituents used in improving only performance is alsoincluded in the scope of the present disclosure.

Various advantages and features of the present disclosure and methodsaccomplishing the same will become apparent from the following detaileddescription of embodiments with reference to the accompanying drawings.However, the present disclosure is not limited to the embodimentsdisclosed herein but will be implemented in various forms. Theembodiments have made disclosure of the present disclosure complete andare provided so that those skilled in the art can easily understand thescope of the present disclosure. Therefore, the present disclosure willbe defined by the scope of the appended claims. Like reference numeralsthroughout the description denote like elements.

In this case, it may be understood that each block of processing flowcharts and combinations of the flow charts may be performed by computerprogram instructions. Since these computer program instructions may bemounted in processors for a general computer, a special computer, orother programmable data processing apparatuses, these instructionsexecuted by the processors for the computer or the other programmabledata processing apparatuses create means performing functions describedin block(s) of the flow charts. Since these computer programinstructions may also be stored in a computer usable or computerreadable memory of a computer or other programmable data processingapparatuses in order to implement the functions in a specific scheme,the computer program instructions stored in the computer usable orcomputer readable memory may also produce manufacturing articlesincluding instruction means performing the functions described inblock(s) of the flow charts. Since the computer program instructions mayalso be mounted on the computer or the other programmable dataprocessing apparatuses, the instructions performing a series ofoperations on the computer or the other programmable data processingapparatuses to create processes executed by the computer to therebyexecute the computer or the other programmable data processingapparatuses may also provide operations for performing the functionsdescribed in block(s) of the flow charts.

Here, the term ‘˜unit’ used in the present embodiment means software orhardware components, such as field programmable gate array (FPGA) andapplication-specific integrated circuit (ASIC) and the ‘˜unit’ performsany roles. However, the meaning of the ‘˜unit’ is not limited tosoftware or hardware. The ‘˜unit’ may be configured to be in a storagemedium that may be addressed and may also be configured to reproduce oneor more processor. Accordingly, for example, the ‘˜unit’ includescomponents, such as software components, object oriented softwarecomponents, class components, and task components and processors,functions, attributes, procedures, subroutines, segments of programcode, drivers, firmware, microcode, circuit, data, database, datastructures, tables, arrays, and variables. The functions provided in thecomponents and the ‘˜units’ may be combined with a smaller number ofcomponents and the ‘˜units’ or may be further separated into additionalcomponents and ‘˜units’. In addition, the components and the ‘˜units’may also be implemented to reproduce one or more central processingunits (CPUs) within a device or a security multimedia card.

The present disclosure proposes a control and configuration method forultra-wideband transmission/reception in a fifth generation (5G) mobilecommunication system. In particular, a method for scheduling, handover,and radio link failure (RLF) recovery in ultra-wide bandwidth may beconsidered. In the 5G mobile communication system, various services (orslices), such as enhanced Mobile Broadband (eMBB), ultra reliable andlow latency communication (URLLC) and enhanced machine typecommunication (eMTC) are expected to be supported. This may beunderstood in the same context that voice over internet protocol (VoIP),best effort (BE) services, and the like are supported in long termevolution (LTE) which is the 4G mobile communication system. Inaddition, various numerologies are expected to be supported in the 5Gmobile communication system. This may specifically include subcarrierspacing, and the like, which may directly affect a transmission timeinterval (TTI). In addition, various numerologies are expected to besupported in the 5G mobile communication system. This is one of thecharacteristics of the 5G mobile communication system which very differfrom those of the currently standardized LTE which supports only onekind of TTI (for example, 1 ms). If the 5G mobile communication systemsupports a TTI (for example, 0.1 ms, and the like) which is much shorterthan the 1 ms TTI of LTE, it is expected to be very helpful insupporting the URLLC, and the like, which requires a short latency. Inan embodiment of the present disclosure, the numerology may be used asthe term serving as the subcarrier spacing, a subframe length, asymbol/sequence length, cyclic prefix, and the like. In addition, thenumerology may be a cause which makes terminals to have differentbandwidths (BWs). The base station may be represented by variousabbreviations, such as next generation (gNB), evolved node B (eNB), nodeB (NB), and base station (BS). The terminal may be represented byvarious abbreviations, such as UE, MS, STA, and the like.

FIG. 1 is a diagram illustrating a scalable bandwidth (BW) system of LTEaccording to various embodiments of the present disclosure.

Referring to FIG. 1 , the LTE system introduces a concept of a scalableBW to support various BWs and may support terminals having various BWs(e.g., 5/10/20 MHz, and the like) having the same center frequency.

For example, if when the UE 1 is a terminal supporting 5 MHz and the UE2 a terminal supporting 10 MHz, the LTE base station may appropriatelyconfigure a control channel and transmit a control signal so that bothof the UE 1 and UE 2 can receive the control signal. However, thismethod may limit resources available for a terminal supporting arelatively small bandwidth when the entire capable bandwidth of the basestation is very large, that is, in an ultra-wide bandwidth. For example,if the UE 3 is operated at an edge of the used bandwidth of the basestation, the UE 3 may not separately receive the control signal of thebase station.

Therefore, in the 5G NR (new radio) communication system, the terminalhas to be able to transmit and receive important control signals so thatthe terminal maintains the connection with the base station even in abandwidth not supported by the existing scalable BW system. For example,the important control signal may be transmitted through a primary cell(PCell) by a signaling radio bearer (SRB) in the case of the LTE. Inaddition, in the PCell, a control signal for scheduling and hybridautomatic repeat request (HARQ) procedure in the PCell itself and asecondary cell (SCell) may be transmitted/received. Both of the PCelland the SCell of the LTE may be viewed as one independent cell. Inaddition, separate medium access control (MAC) entity and linkadaptation according thereto and HARQ entity are required for each cell.However, in a 5G NR single carrier communication system, the wholebandwidth actually corresponds to one cell. In addition, functions ofthe PCell for connection/connection establishment/maintenance and datatransmission/reception of the terminal should be basically provided.

FIG. 2 is a diagram illustrating various band partitioning schemesaccording to various embodiments of the present disclosure.

Meanwhile, even if the base station is operated in the ultra-widebandwidth, the terminal enables transmission/reception at once only insome of the whole bandwidth because of limited implementation andcomplexity. In order for the terminal to be operated in a bandwidthlarger than a maximum capable BW of the terminal, the terminal cannotbut be operated by being temporally partitioned. For the sake of ease ofultra-wide bandwidth management, the base station may configure thewhole bandwidth by partitioning the whole bandwidth into several bandshaving an appropriate size and instruct the terminal to perform variousMAC functions (e.g., scheduling, measurement, link adaptation,modulation and coding (MCS) scheme, HARQ, and the like) in a specificband. In addition, based on the band, the terminal may determine andreceive the structure of the control channel and the reference signal(RS).

Referring to FIG. 2 , case A illustrates static partitioning. Accordingto the case A, the base station may partition the whole bandwidth into aplurality of bands having the same size. For example, the wholebandwidth may be partitioned into four bands having the same size. Theterminal 1 (UE 1) may support a bandwidth larger than band 1. At thistime, since the base station configures a band to be a fixed size, theterminal 1 may be operated with the base station even in some of theentire capable bandwidth, not in the entire capable bandwidth. Forexample, although the terminal 1 may be operated with the base stationin the band 1, since the remaining bandwidths larger than the bandwidthof the band 1 in the capable bandwidth of the terminal 1 is smaller thanthat of the band 2, the terminal 1 cannot be operated with the basestation in the remaining bandwidths.

Case B illustrates flexible partitioning. According to the case B, thebase station may partition the whole bandwidth into a plurality of bandshaving various sizes. At this time, if the capable bandwidth of theterminal 1 is equal to that of the band 1, the terminal 1 may beoperated with the base station in the entire capable bandwidth. However,in the case of the terminal 2 (UE 2), if the maximum capable bandwidthis smaller than that of band 4 configured by the base station, theoperation of the terminal 2 cannot be supported.

Therefore, as in Case C, a method, such as static partitioning with finegranularity may be considered. According to Case B, the base station maypartition the whole bandwidth by minimizing the unit of the band. Inthis case, since the bandwidth to be used by the terminal may berepresented by a bundle of small bands, it is possible to supportterminals having various sizes of bandwidths. For example, the terminal1 may be operated with the base station through a bundle of bands 1 to6, and the terminal 2 may communicate with the base station through abundle of bands 13 to 16.

On the other hand, in Case C, too many bands may increase a load duringmanagement. Therefore, as in Case D, a method of freely configuring aband size may be useful (flexible partitioning with fine granularity).The method is a method of partitioning a unit of a band into smallpieces while varying the size of the band. In this case, in Case B, theterminal 2 cannot be supported, but in Case D, the terminal 2 may beoperated with the base station through a bundle of bands 6 and 7.

In an embodiment of the present disclosure, in order to address theissue of the method in which the base station partitions the wholebandwidth into bands and configures the bands to be in terminals fromthe cases A to D, the base station configures bands having differentsizes for each terminal. Hereinafter, for the viewpoint of the system amethod of representing a band configured in a terminal by a combinationof sub-bands having the same size will be described. In addition, fromthe viewpoint of the system, the independent scheduling, the linkadaptation, the MCS, the HARQ procedure, or the like are not performedin the partitioned sub-band, like the existing CA, but from theviewpoint of the terminal, the method for performing one scheduling, thelink adaptation, the MCS, the HARQ procedure, or the like in theconfigured band will be described.

FIG. 3 is a diagram of a band partitioning structure according to anembodiment of the present disclosure.

Referring to FIG. 3 , a structure of a physical layer control channelshould be designed to be scalable in one or a plurality of sub-bands inone band. This means that it is possible to support a terminal having aband that may be represented by at least a multiple of sub-bands in theband. However, a terminal having a band larger than a configured banddoes not have to be supported in the band. The size of the band, whichis a bundle of sub-bands, may be determined by at least one of channelcharacteristics, numerology, a control sub-band size, and a minimumpacket size between the terminal and the base station. The terminal mayperform one MAC function set (e.g., scheduling, MCS, HARQ, and the like)for one service. The band may mean some of the whole bandwidth, whichmay be referred to as a bandwidth part (BWP), some bandwidths, or thelike.

Method for Configuring Band or Sub-Band

The base station may configure a sub-band in a terminal by one method ofsystem information (SI) or a radio resource control (RRC) connectionestablishment procedure. For example, the sub-band configuration may berepresented by a resource element (RE), that is, one resource unitconsisting of a subcarrier spacing and a symbol, time of RE, and thenumber of frequency domains. The time domain can be represented by asymbol number, and the frequency domain can be represented by asubcarrier spacing number. The RE may vary according to a type ofnumerology. If the base station partitions the resource into a pluralityof different numerology regions, the length of the symbol and thesubcarrier spacing that configures up the RE in each region may bechanged. Therefore, if supporting a plurality of numerology regions, thebase station needs to set a plurality of RE types in the terminal.Meanwhile, one sub-band may be represented by k REs. The value k may bea value (pre) set to one value regardless of the numerology region.Alternatively, if necessary, the base station may set values for eachnumerology region in the terminal by an additional SI or RRC message.According to an embodiment of the present disclosure, the sub-bandconfiguration may be represented by the number of physical resourceblocks (PRB) and a frequency location (e.g., a position of a centerfrequency).

For the terminal in which sub-band information is set, the base stationmay configure an operating bandwidth of the terminal, that is, a bandbased on a sub-band for an IDLE mode terminal or a connected modeterminal. For example, a band may be configured in the terminal by asub-band index and the number of sub-bands. At this time, although thesub-bands have the same size, the band may have different sizesdepending on the configuration. The band may be configured in theterminal by the SI or RRC message, together with the sub-bandconfiguration or may be configured in the UE by the SI or RRC messageseparately from the sub-band configuration. Therefore, according to theembodiment of the present disclosure, the sub-band may be configured bySI and the band can be configured by the RRC message. On the other hand,since the band is expressed as a basic unit of the sub-band, the networkmay inform the terminal of numerology information to configure the bandby the SI or RRC message. The terminal may accurately identify astructure of one band by combining the numerology information set foreach band and the sub-band information for each numerology. If only oneof the band and the sub-band is configured, in order to obtaininformation on the other, the terminal may obtain the information fromthe information on the configured band or sub-band according to apredetermined rule.

On the other hand, each sub-band is a unit that is differentiated interms of the network, but the band may be configured for each terminal,and the region may also overlap in terms of the network. Further, theposition and number of control sub-bands may be set in the configuredband. A control sub-band may be referred to as a control resource set, acontrol sub-resource, a control channel resource, or the like. Thecontrol sub-band indicates a resource for receiving DCI in a controlchannel that the terminal monitors. According to an embodiment of thepresent disclosure, at least one common control sub-band and controlsub-bands for each terminal may be configured for one band. A DLdownlink (DL) assignment message and/or an UL (uplink) grant message forgeneral scheduling for each terminal may be indicated as controlsub-bands for each terminal. If other bands are not indicated in the DLassignment message and/or the UL grant message, the terminal may acceptthe DL assignment message and/or the UL grant message indicated by thecontrol sub-bands for each terminal as a transmission/receptionindication for the band in which the control sub-bands for each terminalis configured. For example, there may be a one-to-one relationshipbetween the control sub-bands for each terminal and bands.

The resource information for data transmission is indicated by aresource block (RB) unit. At this time, a start (or end) point of afirst RB matches a start (or end) point of a band or may be a locationwhich may be directly calculated from the band and sub-bandconfiguration information. In case of the instruction of the datatransmission/reception resources for the same band, the base station mayinform the terminal of resources allocated to the start points and thenumber of RBs. In the case of an instruction of datatransmission/reception resources for different bands, the base stationneeds to inform the terminal of band index information (band index, bandID, and the like) indicating the band in addition to the RB information.Accordingly, the base station may transmit the configuration informationto the terminal, including the index information per-beam to configureone or more band in the terminal. Meanwhile, the RB information islogically partitioned and the real physical resource may be mapped to acontinuous or discontinuous resource RE. The band index information maybe separately assigned to the DL band or the UL band, and may beassigned in common regardless of the DL/UL band.

As can be seen from the above description, the base station may includethe numerology information in the band setting information in order toinstruct the terminal to configure the band. The terminal may calculatethe RE structure from the numerology information, and may identify thecontrol sub-band and the resource information for data transmissionaccording to the calculated RE structure. Meanwhile, since the locationsand sizes for each band are represented by sub-bands, the base stationcan separately set the numerology applied to the RE structure forconstructing the sub-band in the terminal using the SI or RRC message.The RE structure for configuring the sub-band and the RE structure forconfiguring the band may be different. In addition, the DL band and theUL band may have different configuration information, such as thefrequency location and the numerology, and are linked to the DLoperation and the UL operation of the terminal, respectively, such thatthe DL band and the UL band may be configured separately. The terminalmay perform an operation for the DL control and data reception from theinformation of the band configured in the DL band, and may perform anoperation for the UL control and data transmission from the informationof the band configured in the UL band.

The base station may configure the band and the control sub-bands forthe common/terminal in the terminal from the base station during theswitching from the idle mode to the connected mode. The base station mayconfigure the band information or the control sub-band connected to theband in the terminal through a random access response (RAR) or a message4 (Msg4) (e.g., RRC connection complete) during a random accessprocedure. If there is no separate configuration, the terminal maydetermine the location of the sub-band and the band used in theconnected mode based on at least one of a synchronization signal (SS)bandwidth, an idle mode bandwidth, and a physical random access channel(PRACH) bandwidth according to a predetermined rules. In order toconfigure the band and sub-band configuration and the numerologyinformation required for the operation, the terminal may transmit UEcapability information to the network during a procedure of connectingto the network (e.g., random access or RRC (re)configuration). The UEcapability information may include at least one of the followinginformation: The number of radio frequencies (RFs), a maximum operatingbandwidth of one RF, a maximum operating bandwidth of the terminal, RFretuning latency of the terminal at which the center frequency ismaintained, and RF retuning latency of the terminal at which the centerfrequency is switched, a type of operable numerology, or the like.

Functions that may be provided in the system structure proposed in thepresent disclosure may be considered as follows.

-   -   Configuration of control/RS/CSI report/HARQ feedback per band    -   Self-/cross-band scheduling    -   Band-aggregation to transmit single transport block    -   Cross-band HARQ retransmission    -   Common signaling    -   Band recovery    -   RRM (radio resource management) measurement        Configuration of Control/RS/CSI Report/HARQ Per Band

When setting the band, the base station may inform the terminal of thelocation and the range of the band (e.g., start, size or centerfrequency and bandwidth, and the like) by the multiple of the basic unit(e.g., RB or sub-band). The location and the range of the band are apart of one carrier in which the network system operates, and thereforemay be set by a frequency offset and a bandwidth of a bandwidth respectto a center frequency of the entire carrier bandwidth according to theembodiment. Alternatively, the location and the range of the bandaccording to the embodiment may be set by the frequency offset and thebandwidth of the band with respect to the center frequency at which asynchronization signal detected by the terminal is located.

On the other hand, the center frequency of the carrier bandwidth thatthe terminal understands may be the center frequency of thesynchronization signal detected by the terminal, or may be identical tothe center frequency information of the carrier indicated by the SIconnected to the synchronization signal detected by the terminal or thecenter frequency information of the carrier at which the terminal isinstructed from the base station during the RRC connection establishmentprocedure.

The terminal may understand the band range as a system bandwidth.Therefore, even if bands in different ranges are allocated, the terminaland the base station should be designed to be able to be receivedaccording to the same reception rule. For example, the reference signalRS or the location of the control channel that the base stationtransmits should be able to be transmitted and received based on thestart and size of the band configured in the terminal. In addition, theCSI report or the location of the HARQ feedback that the terminaltransmits should also be able to be transmitted and received based onthe start and size of the band configured in the terminal. Meanwhile,when a plurality of bands are configured in the terminal, the basestation may additionally configure, in the terminal, whether the HARQprocess is shared in the plurality of bands or whether the HARQ processis separated for each band.

The band that is basically monitored by the terminal is referred to as aprimary band (p-band). In a resource area other than the p-band, themonitoring may not be performed in a resource area other than the p-bandbefore a separate control/configuration is performed in the p-band. Asecondary band (s-band) is selectively operated according to theconfiguration through the p-band, and the p-band and the s-band may becalled a first RF band and a second RF band according to the embodiment.In addition, the p-band may be activated to an active state through anRRC message or an MAC CE among at least one configured band candidate.In addition, the s-band may be activated to an active state through theRRC message, the MAC CE, or the DCI among at least one configured bandcandidate. Similarly, the base station may deactivate one or more bandsfrom an active state to an inactive state by transmitting or adeactivation signal/message to the terminal through the RRC message, theMAC CE, or the DCI. In an embodiment of the present disclosure, anactive band and the p-band may be interchangeably used in a similarmeaning. However, according to an embodiment of the present disclosure,the active band and the p-band may be different. For example, when thep-band is configured, the DL band and the UL band may be combined witheach other. In addition, the p-band is a basic active band in one cell,but all active bands are not the p-band. In addition, the p-band may notbe deactivated except for a separate band switch procedure. In the caseof the TDD, the frequency locations of the DL band and the UL band maybe the same, so that the DL band and the UL band may be configured as abundle. The p-band configuration may include at least one DL band and atleast one UL band so that the base station may instruct the terminal. Ifthe terminal reports the UE capability report including the RFinformation to the base station, the base station may set a p-band foreach different RFs of the terminal.

In the p-band or the active DL band, the following operations may befurther considered.

-   -   a) Monitor the UE common information (for RRC Connected UE's))    -   b) Monitor the common per-beam information in above 6 GHz        systems    -   c) Monitor dedicated search spaces for UE specific        configurations and to get configurations for the 2nd RF BW (if        needed))    -   d) Support RRM measurements (this is needed if the RRM BW is        inside the 1st RF BW))

The difference in configuration and operation of the p-band and theactive band will be described. The base station may additionally set thep-band state together with one or more band configuration by the RRCmessage. For the band configured by the p-band, the terminal may beconfigured to receive at least one of 1) RRC message, 2) MAC CE, 3) L2common signaling, 4) L1 common signaling, and 5) UE dedicated signalingonly in the p-band. In addition, the terminal may be configured tooperate at least one of other functions, for example, 1) radio linkmonitoring (RLM), 2) discontinuous reception (DRX), 3) measurement, 4)synchronization, 5) paging, and 6) random access only in the p-band.According to an embodiment of the present disclosure, the base stationmay configure the RLM, the measurement, and the DRX functions in theterminal so that the terminal may be operated not only in the p-band butalso in the s-band.

If the terminal may operate the active band only in one band at a time,then the terminal instructs a band switch or cross-band scheduling toanother s-band (e.g., band #1) in the p-band (e.g., band #0), theterminal needs to deactivate the p-band (band #0) for a while andactivate another s-band (band #1). At this time, the operation of theterminal may be restricted in the switched s-band (band #1) according tothe configuration for each message or function described above. In thisrespect, both the p-band and the s-band may be the active band, but theoperations of the terminal for each band may be different. For example,the terminal operation may be different when the RLM and the RLFfunction are applied only to the p-band and when the RLM and the RLFfunction are applied to both of the p-band and the s-band. If theRLM/RLF is applied only to the p-band, the terminal may not perform theRLM if it does not receive the signal of the base station when beingoperated by activating the s-band, or may not trigger the RLF event evenif it performs the RLM. In this case, this may be replaced by aprocedure of falling back from the s-band to the p-band, which will bedescribed below. If the RLM/RLF is applied to both of the p-band and thes-band, the terminal may trigger RLM and RLF events for the active bandamong all bands configured to be RLM/RLF. The RLM result in the s-bandmay be preset or reflected to RLM/RLF event determination for theserving cell according to the setting of the base station.

As described above, if the base station does not configure the RLM/RLFin the s-band in the terminal, it is possible to support the fallback tothe p-band instead. The terminal may start a fallback timer that isseparately set as it satisfies a condition for determining a receptionerror of a base station signal due to deterioration of channel qualityin the s-band. If the condition that the base station signal is receivedagain is satisfied, the terminal may stop, reset, or restart thefallback timer. If the error condition of base station signal receptioncontinues to be satisfied and thus the fallback timer expires, theterminal may switch the RF to the p-band. After switched to the p-band,the terminal may monitor the effective control channel according to thep-band or commonly set control channel location and DRX setting. If thecondition for successfully receiving the feedback or UL signal of theterminal in the s-band is not satisfied for a predetermined time oruntil a timer expires, the base station may be operated to a controlsignal to the terminal in the effective control channel according to theDRX setting and the location of the control channel configured in theterminal in the p-band.

Meanwhile, the base station and the terminal may perform the p-bandrecovery operation as the performance of the terminal in the p-band isreduced, in which the p-band recovery and the fallback operation may beclassified as the following Table 1.

TABLE 1 p-band recovery fallback Band switch From old p-band From s-bandto p-band to new p-band Time scale Tens of ms Several ms Problem Alleast one of Control channel inactivity determination the existing RLFcondition conditions

On the other hand, one procedure of an activation and deactivationoperation for the band may be as follows. According to an embodiment ofthe present disclosure, the activation/deactivation MAC control element(CE) may be a new MAC CE for the band. Alternatively, according to anembodiment of the present disclosure, the activation/deactivation MAC CEmay reuse the MAC CE for the existing SCell.

If the MAC entity is configured with one or more SBands, the network mayactivate and deactivate the configured SBands.

The network activates and deactivates the SBand(s) by:

-   -   sending the Activation/Deactivation MAC CE;    -   configuring sBandDeactivationTimer timer per configured SBand        (except the SBand configured with PUCCH, if any): the associated        SBand is deactivated upon its expiry.

The MAC entity shall for each NR-UNIT and for each configured SBand:

-   -   1> if an Activation/Deactivation MAC CE is received in this        NR-UNIT activating the SBand:    -   2> activate the SBand:

2> start or restart the SBandDeactivationTimer associated with theSBand.

-   -   1> else if an Activation/Deactivation MAC CE is received in this        NR-UNIT deactivating the SBand; or    -   1> if the SBandDeactivationTimer associated with the activated        SBand expires in this NR-UNIT:    -   2> deactivate the SBand;    -   2> stop the sBandDeactivationTimer associated with the SBand;    -   2> flush all HARQ buffers associated with the SBand.    -   1> if NR-PDCCH on the activated SBand indicates an uplink grant        or downlink assignment; or    -   1> if NR-PDCCH on the Serving Cell scheduling the activated        SBand indicates an uplink grant or a downlink assignment for the        activated SBand:    -   restart the sBandDeactivationTimer associated with the SBand;

Next, an association operation with a band switch/activation indicationin a single active band or multiple active band operation will bedescribed.

The terminal may monitor only at least one of one or more configuredbands according to the RF conditions, and may view one or more of them.Therefore, it may be advantageous in terms of scalability that the bandindication of the base station is commonly applied to the terminals indifferent RF conditions. However, the base station should know other RFconditions of the terminal in advance through the capability report ofthe terminal. Otherwise, there is a possibility of malfunction if thebase station cannot know whether Band #1 is deactivated due to the RFrestriction of the terminal when the base station issues an activationindication for Band #2 to any terminal in Band #1.

If a terminal operated in a single active band receives a bandactivation indication of a base station, the previous band isdeactivated while switched to the indicated band (i.e., activating theindicated band). In addition, if a terminal operated in multiple activebands receives a band activation indication of a base station, theindicated band may be activated and maintain a band which is in use bybeing activated in advance.

In this way, an estimated approach by the capability report of theterminal is simple, but may still have a possibility of malfunction. Fora clear procedure and operation, the base station should be able to setthe maximum number of active bands of the terminal and to clearlyindicate the deactivation of the bands.

The terminal may be set in advance whether to operate the active bandaccording to any of the following two methods or set by the basestation/network. In addition, the operation may be identically appliedto a case where a band switch/activation is performed in conjunctionwith a cross-band scheduling indication in addition to a separate bandactivation indication of the base station.

a) Multiple active bands are configured, but each active band may beonly switched to another deactivated band. Therefore, it is possible tochange the number of active bands only by RRC messages (the number ofactive bands may be changed by SI, DCI, MAC CE, and the like, accordingto the embodiment).

b) Multiple active bands are configured, and the base station can givethe terminal the activated/deactivated indication for each band. Sincethe number of active bands can be changed, the network may be operatedso that the number of active bands does not exceed the maximum number ofactive bands of the terminal or all bands are deactivated. If the basestation indicates the number of active bands to exceed the maximumactive band of the terminal, the terminal may be operated by at leastone of 1) deactivation of the first activated band, 2) deactivation ofthe last activated band, 3) deactivation of the lowest band according tothe band index sequence, 4) deactivation of the band with the lowestpriority among the bands set by the base station, and 5) deactivation ofthe band arbitrarily determined by the terminal among the previousactive bands. The determination of the band to be deactivated may bemade to exclude the p-band.

The procedure of determining the movement time including retuninglatency at the time of activating a band with DCI or MAC CE will bedescribed.

The terminal may change the RF retuning time according to therelationship between the active band switch condition and the switchingband. The base station may set in the terminal, for example, a timerequired to switch to another band with respect to one band (forexample, p-band) based on the capability report by the RRC message. Ifthe terminal does not comply with the setting, the terminal may performa reject per band.

When the base station instructs the terminal to perform the bandactivation by the DCI, the terminal 1) may monitor the fastest validcontrol channel in the band activated after the switching time axis onthe band ID included in the DCI, based on the switching latency from theDCI receiving time (e.g., subframe/slot/minislot, and the like) presetby the RRC message to the switching complete or 2) monitor the fastestvalid control channel after the time determined depending on a k value,by specifying in the DCI the switching latency k from the DCI receivingtime (e.g., subframe/slot/minislot, and the like) to the switchingcomplete, along with the band ID.

When the base station instructs the terminal to perform the bandactivation by the MAC CE, the terminal may be operated by at least oneof 1) monitoring the fastest control channel valid in the band activatedafter the switching latency from the HARQ acknowledgment (ACK) successtime (e.g., subframe/slot, minislot, and the like) for the MAC CEreception to the switching complete based on the band ID included in theMAC CE, based on the switching time preset by the RRC message, 2)monitoring the fastest control channel valid in the band activated afterthe switching latency from the time (e.g., subframe/slot/minislot, andthe like) when the indication drops to the PHY again by analyzing theMAC CE and allowing the MAC to determine the band switch based on theband ID included in the MAC CE, based on the switching latency preset bythe RRC message, 3) monitor the fastest valid control channel in theband activated after the switching latency from the time when the MAC CEreception success time (e.g., subframe/slot/minislot, and the like) tothe switching complete, by specifying in the MAC CE the switchinglatency k from the MAC CE reception success time (e.g.,subframe/slot/minislot, and the like) to the switching complete, alongwith the band ID, and 4) monitor the fastest valid control channel inthe band activated after the switching latency from the HARQ ACK successtime (e.g., subframe/slot/minislot, and the like) for the MAC CEreception success time to the switching complete, by specifying in theMAC CE the switching latency k from the HARQ ACK transmission time(e.g., subframe/slot/minislot, and the like) for the MAC CE receptionsuccess to the switching complete, along with the band ID.

The base station can separately instruct the terminal to perform theband configuration and the CSI-RS configuration. In order to control theCSI-RS measurement and reporting for each band of the UE, the basestation may instruct the terminal to report the measurement resultaccording to at least one of the following methods. The terminal maymeasure the CSI-RS indicated by the base station and report the resultaccording to the CSI-RS report setting interlocked with the CSI-RSresource.

-   -   1) If the mapping information between the band and the CSI-RS        resource is set:

The base station may set the mapping information between the band andthe CSI-RS resource in the terminal by the RRC message. The mappinginformation may include information on the band configuration or theCSI-RS resource (measurement/report) configuration. The base station maytransmit a band index to the terminal in order to indicate the bandswitch, and the terminal may perform the measurement and reporting onthe CSI-RS determined based on the band index and the mappinginformation.

-   -   2) If the mapping information between the band and the CSI-RS        resource is not set:

a) The base station may transmit the band index and the CSI-RS resourceindex to the terminal in order to indicate the band switch, and theterminal may perform the measurement and report on the indicated CSI-RS.

b) The base station may transmit the band index to the terminal toindicate the band switch. The terminal may identify the CSI-RS resourcesincluded in the active band by the implementation and report theidentified CSI-RS to the base station, including the index of theidentified CSI-RS resource after the measurement for the identifiedCSI-RS.

The base station can separately instruct the terminal to perform theband configuration and the CSI-RS configuration. In order to set thecommon CSI-RS for the plurality of bands of the terminal and control themeasurement and reporting, the base station may instruct the terminal toreport the measurement result according to at least one of the followingmethods. 1) The terminal may measure the CSI-RS indicated by the basestation and report the result to the base station according to theCSI-RS report setting interlocked with the CSI-RS resource. 2) The basestation transmits the band index to the terminal to indicate the bandswitch, and the terminal may report to the base station after measuringthe CSI-RS currently included in the active band.

Self-/Cross-Band Scheduling

FIG. 4A is a diagram illustrating an operating downlink datatransmission/reception scheduling and uplink data transmission/receptionscheduling according to an embodiment of the present disclosure and FIG.4B is a diagram illustrating downlink data scheduling scheme accordingto an embodiment of the present disclosure.

Referring to FIGS. 4A and 4B, the base station may controltransmission/reception in a control channel or a data channel of theterminal through a control sub-band (c-sub-band) within the p-bandconfigured in each terminal. The base station may instruct the terminalto transmit or receive a DL (downlink) data transmission/receptionregion or an uplink (UL) data transmission/reception area by self-banddata scheduling or cross-band data scheduling. In addition, the basestation may also instruct the terminal to change the location/size ofthe control sub-band in the same band by the self-band controlscheduling. In addition, the base station may also instruct the terminalto change the location/size of an additional control sub-band in anotherband by the cross-band control scheduling. It is possible to furtherindicate the location (e.g., subframe, slot, minislot, symbol, and thelike) of the time resource as well as the location of the frequencyresource at the time indicating the location of the control sub-band inthe same or another band.

In the case of the uplink scheduling, a preset latency value (e.g., 4ms) or a separate latency value may be indicated to the UE through thecontrol sub-band. A physical downlink shared channel (PDSCH) and a PDSCHfor data transmission/reception in the same subframe may be indicated.In the system considered in an embodiment of the present disclosure, inthe case of the cross-band scheduling in which a bandwidth needs to bechanged even in downlink scheduling, a specific subframe (or a slot, asymbol, and the like) (subframe for downlink data transmission) may berequired to be indicated separately. This is because the processing timefor a radio frequency) and retuning of a baseband (BB) circuit may berequired as the location of the band to be used suddenly is changed.Therefore, by considering the capable band information carried on thecapability report of the terminal and the degree of change of the usedbandwidth of the terminal by the control operation of the base station,the base station may transmit the control signal and then indicate(delayed grant) the transmission/reception of the downlink resourceafter a preset latency, For example, if transmission of the PDSCH startswithin a predetermined time (e.g., k symbols) after the transmission ofthe control signal on the PDCCH, the PDCCH and the PDSCH may exist inthe same band. However, if the transmission of the PDSCH starts at atime larger than the predetermined time (e.g., k symbols) after thetransmission of the control signal on the PDCCH, the PDCCH and the PDSCHmay exist in different bands.

Referring to FIG. 4A, the operations of performing the self-bandscheduling and the cross-band scheduling for the data transmission andreception, and performing the self-band scheduling and the cross-bandscheduling for the uplink data transmission and reception are brieflyillustrated. The latency may be included in each control signal (e.g.,DCI, MAC CE, or the like) or at least one latency value may be set inthe terminal in advance for each s-band during a capability negotiationand connection establishment/reconfiguration procedure of the terminal.Since the delay in the case where the used bandwidth of the terminalcompletely changes is greater than in the case where the used bandwidthof the terminal partially overlaps but the bandwidth only changes, thebase station may transmit the latency to the terminal by each controlsignal based on the situation or transmits the indices for two more thanlatency values to the terminal by the control signal, such that theterminal is appropriately delayed and then perform the downlinkreception operation. If the delay value is set to be 0 or is not set,the terminal may perform the operation of receiving the downlink data inthe same TTI (or transmission time unit (TTU)).

The terminal may discard the downlink data reception of the base stationwhen it is predicted that the band switch depending on the latency valuewill fail or fails. According to the configuration of the base station,the terminal may report to the base station the transport block (TB)discarding the data reception or the information on the discard(reception failure) of the terminal with the feedback information on theHARQ process ID.

In the band switch operation, the latency value may differ depending onwhether the center frequency of the actual RF band of the terminal isswitched. For example, in the case of a TDD terminal, the delay does notalways occur for switching between the DL band and the UL band but mayoccur only when the center frequencies of the DL band and the UL bandare switched.

As illustrated in FIG. 4A, a location of another band or a location of acontrol sub-band within another band may be notified by the controlsub-band within one band. The terminal may switch the RF to receive thecontrol sub-band of another band (e.g., band 2) in one band (e.g.,band 1) according to the instruction of the network, and receive thedata reception or transmission information of the downlink or uplinkdata in the control sub-band of the band 2. In addition, the controlsub-band within one band may inform the terminal of the location of theband including the control sub-band and/or the data region of anotherband not including the control sub-band.

FIG. 4B illustrates three types of band scheduling schemes in the caseof the downlink. The terminal may configure the first band (Band #1) andthe second band (Band #2) based on the RRC connection establishment orRRC reconfiguration procedure. Here, it is assumed that the size of thefirst band is smaller than that of the second band, and the size of thesecond band is equal to the maximum operating bandwidth of the terminal.For example, the size of the first band may be a size of four sub-bands(sub-band 7-10), the size of the second band may be the size of sixsub-bands (sub-band 1-6), the maximum operation band of the terminal mayequal to the size of six sub-bands. In addition, the terminal maymonitor the control signal in the first band having a small size toreduce power consumption.

First, the operation referred to as the self-band scheduling will bedescribed. The terminal may receive a DL control signal from a basestation in an nth slot through a first band and receive the downlinkcontrol signal transmitted by the base station in the same first band asthe control signal according to the indication of the control signal.The time resource location (e.g., start location and interval) of thedata channel may be statically set for each terminal or may bedynamically indicated using the index in the slot or symbol unit by thedownlink control signal. The scheme for indicating the self-bandscheduling may inform the band index in the downlink control signal, aformat of a specific control signal (e.g., when latency or resourcestart location information considering latency is not included in acontrol signal, or the like), or the like.

Next, the operation referred to as the self-band scheduling will bedescribed. The terminal may receive the downlink control signal from thebase station in a (n+1) th slot through the first band, and receive datatransmitted from the base station in a (n+2) th slot of the second band.The time resource location (e.g., start location and interval) of thedata channel may be statically set for each terminal or may bedynamically indicated using the index in the slot or symbol unit by thedownlink control signal. The length of the slot or the symbol may becalculated again based on the numerology information configured in thededicated band. If the terminal is instructed to receive data afterreceiving the control signal at a shorter interval than the RF retuninglatency previously reported by the mistake of the base station, theterminal 1) may inform the base station of cause information, such asthe information that there is a problem in the cross-band scheduling orthe information that there is the RF retuning information error bytransmitting an RRC connection reconfiguration request, or 2) performthe p-band or active band switch/setup request to the base stationthrough the RRC message or the MAC CE.

Next, the operation of implementing the operation, such as thecross-band scheduling by the band indication and the self-bandscheduling will be described. The terminal may receive the downlinkcontrol signal from the base station in an n+3th slot through the firstband, and receive the downlink control signal of the second bandaccording to the indication of the downlink control signal.Specifically, based on at least one information of the band indexincluded in the downlink control signal and the downlink control channelresource location, the terminal may monitor the downlink control channelof the second band by switching a band. If the downlink control channelresource location is not separately indicated, the terminal may monitorthe downlink control channel at the earliest point after the completionof the RF retuning according to the downlink control channel for eachband configured by the RRC message and the resource information thereof.In order to know when the terminal monitors the downlink controlchannel, the base station may determine the time when the base stationtransmits the control signal to the terminal and the location of thedownlink control signal to be monitored by the terminal, based on the RFretuning latency values for each terminal that is determined accordingto the information related to the RF retuning latency reported to the UEcapability.

On the other hand, the indication for the self-band scheduling operationand the cross-band scheduling operation or the band indication operationmay simultaneously drop to the terminal in the downlink control channel.If the self-band scheduling operation and the cross-band schedulingoperation collide with each other, for example, in the situation whereRF retuning cannot be performed while data is being received, theterminal 1) may always prioritize the self-band scheduling operation, or2) prioritize the data transmission/reception operation determined asthe high priority according to the priority (e.g., based on at least oneof numerology, control signal format, traffic, service, band, PDU size,and delay requirement). If the self-band scheduling and the bandindication operation are concurrently indicated, the terminal maymonitor the downlink control channel at the earliest time after the RFretuning latency after the data transmission/reception according to theself-band scheduling indication is completed.

According to an embodiment of the present disclosure, the base stationis not allowed to indicate the scheduling operation that is not feasiblewithin the retuning latency of the terminal.

Meanwhile, the base station may configure an asymmetric p-band havingwith different bands (e.g., location, size, and the like) in downlinkand uplink for one terminal. However, the p-band needs to support boththe downlink and the uplink to smoothly operate the main controlfunctions. Therefore, even if different bands are allocated, theterminal may be understood as one p-band.

As described above, the cross-band scheduling may be indicated by 1) onesignal of the DCI/MAC CE signal for the cross-band scheduling or 2) twosignals for the band switch/activation indication (e.g., DCI/MAC CE) andthe self-band scheduling. In general, the p-band is not changed by thecross-band scheduling, but it may be useful to transfer the p-bandfunction if the function in the p-band is to be maintained during theband switch. As in 1), if the indication is made by one signal, the basestation should set whether the p-band is switched in the terminal inadvance by in the RRC message or include whether the p-band is switchedin the DCI/MAC CE. As in 2), if the indication is made by two signals,the base station should set whether the p-band associated with the bandswitch/activation indication is switched in the terminal in advance byin the RRC message or include whether the p-band is switched in theDCI/MAC CE.

On the other hand, as illustrated in FIG. 4A, a region to which thecontrol signals of each band are transmitted may be designated as aspecific sub-band. For example, the control region may be allocated to aspecific frequency region of the band. For example, in the case of theband 1, sub-band 1 may be the region in which the control signal istransmitted. Alternatively, as illustrated in FIG. 4B, the region wherethe control signals of each band are transmitted is not located at thespecific sub-band, but may be located over the bandwidth of the band.For example, the resource area to which the control signal istransmitted may not be allocated only to a specific frequency region butmay be located over the whole bandwidth of the band for a specific time.

According to an embodiment of the present disclosure, the base stationmay set the terminal or define the operation according to the standardso that after the band switch of the terminal and the DL/UL datatransmission/reception according to the cross-band scheduling, theoperation is performed by at least one of 1) monitoring the controlsignal by returning the terminal to the band receiving the DL assignmentor UL grant, that is, the scheduling indication, 2) monitoring thecontrol signal by locating the terminal in the band that is the targetof the scheduling indication, or 3) monitoring the control signal byswitching the terminal to the band configured by the base station.

In addition, the time when the monitoring bandwidth is applied accordingto the scheduling may be immediately after transmitting or receiving oneDL/UL data transport block in the indicated band, or after the terminaldetermines that the condition satisfies the condition set by the basestation. The conditions set by the base station may be at least one ofa) the number of scheduling indications for the band, b) the completetime including the HARQ retransmission up to the N-thtransmission/reception transport block, and c) the time (orcorresponding timer, and the like) staying in the current monitoringbandwidth after the first cross-band scheduling indication, d) the time(or corresponding timer, and the like) during which the schedulingindication for the corresponding band was received on the successivePDCCH, e) the number of PDCCHs for which the scheduling indication forthe current monitoring bandwidth is not received, f) the continuous time(or corresponding timer, and the like) of the PDCCH interval in whichthe scheduling indication for the current monitoring bandwidth is notreceived.

Band-Aggregation to Transmit Single Transport Block

According to an embodiment of the present disclosure, in order to reducepower consumption, the base station configures a band having a sizesmaller than a capable band of a terminal in the terminal as the p-band,and when a large amount of data is required to be transmitted andreceived, the cross-band scheduling may be indicated so as to transmitand receive a signal in a resource of a secondary band (s-band) resourceset for a larger band. In this case, if the p-band and the s-band are acompletely separated band, the terminal may be able to buffer the signalfor the corresponding band only after a delay (for example, hundreds ofμs level). Therefore, it may be difficult to simultaneously transmit andreceive a signal to the control channel and the data channel in the samesubframe. However, if the p-band is included in the s-band as afrequency resource, the delay for RF/BB retuning is small (for example,several μs level), such that the control channel and the data channelcan be simultaneously transmitted/received in the same subframe. At thistime, if a different transport blocks are sent in the physical resourceblock (PRB) of the p-band and the PRB of the s-band, additional resourceallocation (for example, in DCI) and HARQ process is inevitablyrequired. Therefore, a method of transmitting one transport block bybundling different PRBs of the p-band and the s-band may be considered.The method should be able to bundle and transmit one transport blockeven if different numerologies are applied in each band. The basestation may use at least one of the following methods to instruct theterminal to perform band aggregation.

1) The base station may assign a new band ID by setting the aggregatedband (band 1+band 2) as an additional band 3 and issue an instruction toperform the aggregation for the band 1 and the band 2 by the band ID ofthe band 3 in the DL control indicator (DCI) transmitted through the DLcontrol channel.

2) The base station may indicate the band 2 to be aggregated in theterminal through the DCI transmitted through the DL control channel ofthe p-band (band 1) by the band ID. The DCI for the band 2 may betransmitted in the p-band or the band 2. The terminal may perform theaggregation for the p-band (band 1) and the band 2 based on the band IDinformation.

Cross-Band HARQ Retransmission

FIG. 5 is a diagram illustrating a relationship between HARQ and a bandaccording to an embodiment of the present disclosure. According to anembodiment of the present disclosure, the terminal and/or the basestation may perform a retransmission in another band for a transportblock that fails to transmit in one band.

Referring to FIG. 5 , the HARQ for the transmission failure in one bandcan be retransmitted in another band. For example, if the downlinktransmission failure occurs in the band 1 when bands 1 to 3 areconfigured in the terminal, the base station can perform the downlinkdata retransmission in the band 2. For this purpose, the scheduling andthe priority handling may be made. The multiplexing may be performedwhen data to be transmitted exists in a band for transmitting theretransmission data.

In the case of the downlink, the base station can perform theretransmission in different bands according to the implementation byself-/cross-band scheduling. Such an operation can be performedaccording to the determination of the base station in the downlink, butit can be helpful in the determination of the base station on which bandis suitable for retransmission based on the uplink signal of theterminal. For example, the base station may periodically or dynamicallyallocate uplink resources for the signal transmission to the s-band ofthe terminal. When the terminal determines that the quality of the basestation signal received in the p-band or the quality/error of thereceived data channel is more than a certain level, the terminal maytransmit the uplink signal in the transmission resource of the allocateds-band. The base station may instruct the operation of retransmittingthe downlink data in the s-band based on the quality of the uplinksignal of the terminal. According to another embodiment of the presentdisclosure, a band ID of a candidate s-band which may be used forretransmission is transmitted to the base station along with the HARQfeedback signal of the UE, so that the base station may determine aretransmission operation based on the candidate band report of theterminal.

On the other hand, although a scheme similar to the downlink may beapplied even to the uplink, it takes much delay for the base station toperform the uplink resource allocation (UL grant) again after theterminal receives the reference signal or the feedback signal of thebase station and the terminal notifies the base station of a responsethereto. This is because a certain delay is required after the terminalis instructed by the base station to transmit the uplink signal.Therefore, in the uplink, the terminal first transmits a UL signal (forexample, PRACH, SRS, and the like) through the UL resource allocated ina plurality of bands and the base station receives the UL signal andthen determine the band in which the UL grant is indicate.

In the HARQ procedure, the base station and the terminal may explicitlyrefer to a HARQ process ID in a specific band at the time oftransmitting a control signal in the DCI or the UCI and a HARQ feedbackmessage using a band ID in addition to the HARQ process ID. If it isindicated without the band ID, it is necessary to allocate a largenumber of HARQ process IDs in proportion to the number of bands orrestrict the use of the same HARQ process ID between bands. However,considering operation, such as cross-band HARQ retransmission,restricting the HARQ process ID between bands makes it difficult toobtain additional performance.

The physical uplink control channel (PUCCH) for the UCI transmission forthe HARQ feedback of the terminal may be allocated as the RRC messagethrough the p-band. According to the embodiment of the presentdisclosure, it may be operated at least one of 1) dynamically allocatingthe PUCCH to the s-band through the control sub-band of the p-band, orb) allocating the control sub-band belonging to the p-band is configuredand the PUCCH to the same s-band through the control sub-band, accordingto the configuration of the base station. The terminal may piggyback andtransmit the UCI when the resource is allocated to the PUSCH in thes-band.

In order to support the cross-band HARQ retransmission, even if one bandis deactivated, the terminal may continuously store the HARQ bufferstored for retransmission without flush. The terminal may flush the HARQbuffer only when the cell is released or deactivated.

In the HARQ operation according to the band switching, each band may beconfigured to a different HARQ control variable (for example, HARQACK/negative acknowledgment (NACK) timing, Round Trip Time, HARQretransmission timer, and the like). The terminal may change the HARQoperation according to the HARQ control variable associated with thecorresponding band for the HARQ operation indication including the bandindex.

Common Signaling

FIG. 6 is a diagram illustrating a first operation of transmitting acommon signal from a higher layer to a terminal according to anembodiment of the present disclosure, FIG. 7 is a diagram illustrating asecond operation of transmitting a common signal from a higher layer toa terminal according to an embodiment of the present disclosure, FIG. 8is a diagram illustrating a third operation of transmitting a commonsignal from a higher layer to a terminal according to an embodiment ofthe present disclosure, FIG. 9 is a diagram illustrating a fourthoperation of transmitting a common signal from a higher layer to aterminal according to an embodiment of the present disclosure, and FIG.10 is a diagram illustrating control sub-band structures according to anembodiment of the present disclosure.

The base station may be operated by setting in the terminal the factthat a SRB is transmitted to a primary control sub-band (PCS) in thep-band or a data resource set through the PCS. The base station and/orthe terminal may transmit and receive a RRC message or a non-accessstratum (NAS) message through the SRB. For example, a paging message istransmitted from a mobility management entity (MME) to a terminalthrough a NAS message. The base station may be operated by setting inthe terminal the fact that a data radio bearer (DRB) is transmitted to asecondary control sub-band (SCS) in the p-band or a data resource setthrough the SCS. The PCS or the p-band may be operated so that theterminal is the same as the control resource or its bandwidth (i.e.,access bandwidth) that is operated in common during the initial accessprocedure. For example, in the case of the paging message, the operationscenario may be different depending on the state of the terminal. In thecase of an idle mode UE, the paging message may be received from acertain resource that may be obtained from a synchronization signal anda physical layer (PHY) broadcast channel (PBCH), or a paging message maybe received from a paging resource received from SI. In case of aninactive mode UE (i.e., a state in which some of the connectedoperations are omitted while a base station (RAN) maintains UE contextfor power saving in a connected state), a paging receiving procedure maybe performed according to a paging operation and a paging resource setby the RRC message in the connected state. Meanwhile, the pagingresource set in the connected state may be different from the accessbandwidth.

Meanwhile, in case of a connected mode UE, an operation of receiving theSI or paging message received on the downlink shared channel in thep-band should be considered. If the connected mode UE receives thepaging message, the paging message may be a paging message correspondingto another service/slice. Since the terminal may see only a part of thebands corresponding to the configured band of the whole system bands,the base station may have a burden to separately transmit a commonsignal dropping from the higher layer, for example, an SI message fordifferent terminals for viewing different bands.

Referring to FIG. 6 , the base station may copy SI information (commonsignal) 610 into three and transmit each of the three copied signals620, 623, and 625 to three terminals (UE 1/UE 2/UE 3) through separatecontrol channels (e.g., (c-sub-band 1, c-sub-band 5, and c-sub-band 12).At this time, if the common signal 610 is the paging message, the basestation interprets the paging message and requires an effort to generatepaging messages for each band 630, 633, and 635 for the terminals UE 1,UE 2, and UE 3 included in the bands 630, 633, and 635 and transmit thepaging messages to the terminals UE 1, UE 2, and UE 3.

According to the paging configuration, the paging transmissionopportunity may be determined according to a system frame number (SNF)and a subframe index. The idle mode UE sets the paging transmissionopportunity from the MME and monitors the downlink control channel(PDCCH) in the frame and the subframe corresponding to the set pagingtransmission opportunity even if passing through several base stationsto receive the paging message as resources identified by a paging radionetwork temporary identifier (P-RNTI). More specifically, the terminalmay set as a first paging opportunity a subframe (paging occasion) ofhow many frames (paging frame) are located based on system frame 0 andset a paging opportunity as being repeated for each DRX cyclerepresented in a frame unit. The paging frame number and the pagingoccasion in the paging configuration may be set in the terminal byallowing the base station to directly transmit the value to theterminal, but in the case of the paging frame number, the terminal mayperform the calculation based on other parameters (e.g., DRX cycle, thenumber of paging frames in the DRX cycle, the number of paging occasionsin the DRX cycle, the terminal ID, and the like) or in the case of thepaging occasion, may perform the calculation based on other variables(e.g., the number of paging frames in the DRX cycle, the number ofpaging occasions in the DRX cycle, the terminal ID, the number ofsubframes in the paging frame, and the like).

On the other hand, the detailed equations for the paging configurationrefer to a part of the specification document below.

One Paging Frame (PF) is one Radio Frame, which may contain one ormultiple Paging Occasion(s). When DRX is used the UE needs only tomonitor one PO per DRX cycle.

One Paging Narrowband (PNB) is one narrowband, on which the UE performsthe paging message reception.

PF, PO, and PNB are determined by following equations using the DRXparameters provided in SI:

PF is given by following equation:SFN mod T=(T div N)*(UE_ID mod N)

Index i_s pointing to PO from subframe pattern defined in 7.2 will bederived from following calculation:i_s=floor(UE_ID/N)mod Ns

If P-RNTI is monitored on MPDCCH, the PNB is determined by the followingequation:PNB=floor(UE_ID/(N*Ns))mod Nn

SI DRX parameters stored in the UE shall be updated locally in the UEwhenever the DRX parameter values are changed in SI. If the UE has noIMSI, for instance when making an emergency call without USIM, the UEshall use as default identity UE_ID=0 in the PF, i_s, and PNB equationsabove.

The following Parameters are used for the calculation of the PF, i_s,and PNB:

-   -   T: DRX cycle of the UE. Except for NB-IoT, if a UE specific        extended DRX value of 512 radio frames is configured by higher        layers according to 7.3, T=512. Otherwise, T is determined by        the shortest of the UE specific DRX value, if allocated by        higher layers, and a default DRX value broadcast in SI. If UE        specific DRX is not configured by higher layers, the default        value is applied. UE specific DRX is not applicable for NB-IoT.    -   nB: 4T, 2T, T, T/2, T/4, T/8, T/16, T/32, T/64, T/128, and        T/256, and for NB-IoT also T/512, and T/1024.    -   N; min(T,nB)    -   Ns: max(1,nB/T)    -   Nn: number of paging narrowbands provided in SI    -   UE_ID:

IMSI mod 1024, if P-RNTI is monitored on PDCCH.

IMSI mod 4096, if P-RNTI is monitored on NPDCCH.

IMSI mod 16384, if P-RNTI is monitored on MPDCCH.

The DRX cycle includes a value set by the NAS for each terminal and acommon setting value of the base station, and the smaller of the valueand the common setting value may be used if both are set. However, in anembodiment of the present disclosure, a plurality of common signalingresources may be set in one subframe (or slot), and therefore if thepaging configuration method of the MME may identify the common signalingresource considering the common signaling resources, It is possible toprevent waste caused by copying common signaling resources to aplurality of common signaling resources. According to an embodiment ofthe present disclosure, if there is only one common signaling resourcein a band, a band index and a common signaling resource index can beused equally. According to an embodiment of the present disclosure, if aplurality of common signaling resources in a band are allocated, acommon signaling resource index is used. To this end, an additionalcommon signaling resource index may be configured when a commonsignaling resource is allocated to a specific band by the RRC message.

According to a first method for reducing a waste of common signalingmessage, the common band index may be calculated based on at least oneof an existing system frame number, a subframe, DRX cycle information,or other information for obtaining such information in the pagingconfiguration. For example, the terminal ID may take modular arithmeticby the number (Ncs) of common signaling resources that the base stationhas set as SI to specify one of the common signaling resources. Theterminal ID may be any value derived from an international mobilesubscriber identity (IMSI) or an IMSI. According to another example, theband/common signaling resource index may be calculated based on anoutput value of a function that uses a value of at least one of the DRXcycle, the number of paging frames in the DRX cycle, the number ofpaging occasions in the DRX cycle, the terminal ID, and the number ofsubframes in the paging frame, and the number of common band/commonsignaling resources as an input of a function.

According to a second method for reducing a waste of common signalingmessage, the equation for i_s of the two variables Ns and i_s necessaryfor the existing index pointing equation is as follows: i_s=floor(UE_ID/N) mod Nsi_s=(floor (UE_ID/N) mod Ns) mod Ncs or i_s=floor(UE_ID/(N*Ns)) mod Ncs equation may be used by changing the i_s=floor(UE_ID/N) mod Ns.

For example, the base station and the terminal may calculate a pagingoccasion (PO) using the following [Table 2]. If Ns is 1 and i_s is 0, POis 9, so paging can be received in a 9th subframe.

TABLE 2 PO when PO when PO when PO when Ns i_s = 0 i_s = 1 i_s = 2 i_s =3 1 9 N/A N/A N/A 2 4 9 N/A N/A 4 0 4 5 9

According to a third method for reducing a waste of common signalingmessage, the terminal may receive the common band or the commonsignaling resource from the base station by the RRC message in the RRCconnection state. The idle mode UE in which a terminal does not receivethe common band or the common signaling resource from the base stationthat the terminal newly camps may first perform a random accessprocedure to receive the common signaling resource from the base stationthrough the RRC message.

According to a fourth method for reducing a waste of a common signalingmessage, the paging configuration of the MME is the same as the priorart, and only a band or a common signaling resource monitored by aterminal among a plurality of resources in a specific period may beallocated in one base station. When the base station receives the pagingmessage from the MME, the base station may calculate a maximum value Np(e.g., the number of frames×the number of common signaling resources insubframes) of the paging resource within a period set based on theinformation (e.g., at least one of UE_ID, IMSI, or the like) of theterminal receiving the paging. The base station may determine an indexfor one resource according to an equation of (UE_ID) mod Np. The basestation/terminal may determine a resource to receive paging in the setperiod in such a manner to count the common signaling resources in thesubframe using the index of the determined resource.

The above-described various methods can be roughly classified into thefollowing three methods: 1) A method for determining paging occasionsfor each terminal by using one equation for time axis information (e.g.,paging frame and paging subframe), and then determining resources foreach terminal by another equation for frequency axis information (e.g.,band index or common signaling resource index), 2) A method ofone-dimensionally aligning paging resources over the time axis and thefrequency axis and then determining paging resources for each terminalby one equation, and 3) a method for selecting a part of pagingresources by one equation for the time axis and the frequency axis,one-dimensionally aligning the selected paging resource, and thendetermining the paging resources for each terminal by another equation.

The paging operation described above may operate in a similar mannereven when the terminal is in the inactive mode other than the IDLE mode.

The above-described paging resource may be set as a plurality of pagingresource areas identified for service/numerology/slice support. When theterminal is operated by a specific service/numerology/slice, the pagingreception operation may be performed in the corresponding pagingresource area. When the terminal is operated for a plurality ofservices/numerologies/slices, 1) the base station transmits pagingsignals for each of a plurality of paging resource areas to the terminalin an overlapping manner, or 2) the base station transmits only pagingsignal for one paging resource area to the terminal and simultaneouslymonitors the paging occasions of the plurality of paging resource areas,or 3) the base station may transmit the paging signal to the terminal inthe paging resource area corresponding to one service/numerology/sliceselected according to the set priority and the terminal may also monitorthe paging occasion of the paging resource area. To support theoperation, the base station may inform the terminal of the relationshipbetween each paging resource area and service/numerology/slice throughSI.

Referring to FIG. 7 , a common band 730 is set so that all terminals canreceive one common signal as in the existing LTE, and the base stationmay set an operation of setting when the terminal receives a common band730 in the terminal in advance by the RRC message. For example, the basestation may be configured to operate the terminal according to at leastone of a) allowing the terminal to receive the common band 730 at aspecific time, or b) giving only the opportunity for the terminal toreceive the common band 730 at a specific time and determining whetherthe terminal receives the common band 730 according to the state of theband in which the terminal is operating, or c) giving only theopportunity for the terminal to receive the common band 730 at aspecific time, and allowing the terminal to receive the common band 730only in the case where there is no operation indicated in a band inwhich the terminal is operating. In an embodiment of the presentdisclosure, at least two of the methods a), b) and c) may be separatelyset.

To relieve the disadvantage that a plurality of signals 720 and 725 arecopied/partitioned to separately transmit a plurality of bands 730, 733,and 735 as illustrated in FIG. 6 , a structure in which one controlsub-band is shared by a plurality of bands 730, 733, and 735 isproposed. For example, c-sub-band 4 may be shared by band 1 730 and band2 733, and c-sub-band 10 may be shared by band 2 733 and band 3 735.Accordingly, the common signals to be copied/partitioned may be reducedto two signals 720 and 725. This scheme is not as efficient as theexample of FIG. 7 , but can dynamically control the inter-band sharedcontrol sub-band to minimize inefficiency.

Referring to FIG. 8 , the base station may copy SI information (commonsignal) 810 into three and transmit each of the two copied signals 820and 825 to three terminals (UE 1/UE 2/UE 3) through separate controlchannels (e.g., (c-sub-band 1, c-sub-band 5, and c-sub-band 12). At thistime, if the common signal 810 is the paging message, the base stationinterprets the paging message and requires an effort to generate pagingmessages for each band 830, 833, and 835 for the terminals UE 1, UE 2,and UE 3 included in the bands 830, 833, and 835 and transmit the pagingmessages to the terminals UE 1, UE 2, and UE 3.

Referring to FIG. 9 , unlike the method of determining whether toreceive a common band illustrated in FIG. 7 according to an RRC messageand a specific condition, the base station may indicate whether todynamically receive a common band 930 through bands (band 1, band 3) 940and 945 configured in each terminal (e.g., UE 1 and UE 3) to theterminal However, in order to simplify the L1 signal, the base stationmay set the location/size of the common band 930 and its controlsub-band (e.g., c-sub-band 8, 9) in the terminal in advance by the RRCmessage. In order to return the terminal to the dedicated band again,the base station may be operated according to at least one of a) amethod for transmitting by a base station, a return (or switch)indication to the terminal in the common band 930, b) a method forsetting it in a terminal to return the terminal to a dedicated bandafter a preset timer expires or setting it in the terminal by the basestation, c) a method for setting it in the terminal in advance so thatthe terminal returns to the dedicated band after performing (e.g.,receiving SI or paging) a targeted operation in the common band 930 orsetting it in the terminal by the base station, or d) a method forreceiving, by a terminal, a p-band change control signal in the commonband 930 and setting a dedicated band as a p-band and moving thededicated band.

In order to operate the various methods described above, various bandsand control sub-band allocation schemes as illustrated in FIG. 10 may besupported.

Referring to FIG. 10 , for example, there may be a separate controlsub-band per band. For example, control sub-band 1 may be allocated toband 1 1010, control sub-band 5 may be assigned to band 2 1013, andcontrol sub-band 13 may be assigned to band 3 1015. According to anembodiment of the present disclosure, a sub-band for data transmissionother than a control sub-band may be shared by a plurality of bands. Forexample, both band 1 1010 and band 2 1013 may share sub-bands 3 and 4 assub-bands for data transmission. As another example, control bands maycommonly be allocated to a plurality of bands (shared control sub-bandsamong bands). For example, band 1 1020 and band 2 1023 may be shared bycontrol sub-band 3. Band 2 1023 and band 3 1025 may share controlsub-band 11. As another example, one common control band may beconfigured so that all terminals can receive one common signal. Forexample, a common band 1030 including control sub-bands 8, 9 for allterminals may be configured.

Band Recovery

Meanwhile, the terminal may perform the handover or the band recoveryprocedure according to the degradation in the signal strength/quality ofthe base station. The handover is a procedure for performing RRCconnection reconfiguration to a target cell according to a determinationof the serving base station in response to the degradation in theserving cell signal strength/quality. On the other hand, the bandrecovery proposed in an embodiment of the present disclosure is aprocedure for resetting the p-band while maintaining the connectionbetween the serving base station and the terminal.

The terminal may be operated by either handover or band recoverydepending on timers, parameters, and weights set as different values foreach procedure. For example, in a sub 6 GHz licensed band, the handovermay be important and in a band above 6 GHz, the band recovery may beimportant. In addition, in the unlicensed band where LBT (listen beforetalk) regulation is applied, the band recovery may be important.According to an embodiment of the present disclosure, the terminal mayalso change the weight according to the operation frequency, not by theconfiguration of the base station.

Analysis contents for the application of the existing RLF conditions tothe band will be described below.

Conditions of RLF Detection of the Related Art

Out-of-sync (T310 expires upon N310 of consecutive OOC (out of coverage)indication from L1)

-   -   → Not applicable to band except the case that p-band is        overlapped to common band

RA (random access) failure (RA problem indication when runningT300/301/304/311)

-   -   → Applicable if RACH (random access channel) is configured via        p-band

RLC (radio link control) indication (reaching maximum # ofretransmission of UL)

-   -   → Not applicable to band, but applicable to cell

HO (hand over) failure (target cell indication, incomplete HO, HO timerexpires)

-   -   → Not directly related to band

Note: If one of 4 conditions is met, RLF is triggered

TABLE 3 TE Timers Function at Start/Stop/Expiry T300 >>Starts at the RRCconnection REQ transmit >>Stops at the Receipt of RRC connection setupor reject message OR at the cell reselection time OR upon abortion ofconnection establishment by Higher layers (L2/L3). >>At the expiryperforms the actions T301 >>Starts at the RRC ConnectionRe-establishment REQUEST >>Stops at the Receipt of RRC Connection Re-establishment OR RRC Connection Re-Establishment REJECT message OR Whenselected cell becomes unsuitable to continue further >>At expiry, it Goto RRC_IDLE mode T303 >>Starts when access is barred while performingRRC CONNECTION ESTABLISHMENT for MO(Mobile Originating) calls >>Stopswhile entering RRC_CONNECTED and upon cell re-selection mode >>Atexpiry, Informs higher layers about barring alleviation T304 >>Starts atthe Receipt of RRC CONNECTION RECONFIGURATION message along withMobility Control Info OR at the receipt of mobility from EUTRA commandmessage including CELL CHANGE ORDER >>Stops at the successful completionof HANDOVER to EUTRA or CELL CHANGE ORDER is met >>At expiry, itperforms action based on need. 1. In the case of CELL CHANGE ORDER fromE-UTRA OR intra E-UTRA handover, initiate the RRC connectionre-establishment procedure. 2. In case of HANDOVER to E-UTRA, performthe actions defined as per the specifications applicable for the sourceRAT.

TABLE 4 TE Timers Function at Start/Stop/Expiry T305 >>starts whenaccess is barred while performing RRC CONNECTION ESTABLISHMENT for MOsignaling >>Stops when entering RRC_CONNECTED and when UE does cellre-selection >> At expiry, Informs higher layers about barringalleviation T310 >>Starts when UE detects PHY layer related problems(when it receives N310 consecutive out-of-sync INDs from lowerlayers) >>Stops 1. When UE receives N311 consecutive in-sync INDs fromlower layers/ 2. Upon triggering the HANDOVER procedure 3. Uponinitiating the CONNECTION RE- ESTABLISHMENT procedure >> At expiry, ifsecurity is not activated it goes to RRC IDLE else it initiates theCONNECTION RE-ESTABLISHMENT Procedure T311 >>Starts while initiating RRCCONNECTION RE- ESTABLISHMENT procedure >>stops upon selection ofsuitable E-UTRA cell OR a cell using another RAT >>At expiry it entersRRC IDLE state T320 >> Starts upon receipt of t320 or upon cell re-selection to E-UTRA from another RAT with validity time configured fordedicated priorities (in which case the remaining validity time isapplied). >>Stops upon entering RRC_CONNECTED state, when PLMN selectionis performed on request by NAS OR upon cell re-selection to anotherRAT >> At expiry, it discards the cell re-selection priority infoprovided by dedicated signaling

TABLE 5 TE Timers Function at Start/Stop/Expiry T321 >>starts uponreceipt of measConfig including a reportConfig with the purpose set toreportCGI >> Stops at either of following cases: 1. Upon acquiring theinformation needed to set all fields of globalCellId for the requestedcell 2. Upon receipt of measConfig that includes removal of thereportConfig with the purpose set to reportCGI >> At expiry initiatesthe measurement reporting procedure, stop performing the relatedmeasurements and remove the corresponding measID

According to the above analysis, other conditions (e.g., OOC, RAfailure, HO failure) except the RLC indication are less likely to beused at the time of applying to the band. In the case of the RLCindication condition, since the terminal is in the connection state withthe serving base station even if the control is impossible by the SRBdue to deterioration in the connection performance of the p-band, theRLF for the serving base station may be determined according to whethera sum of the aggregated RLC packet retransmission frequencies before therecovery timer for the p-band expires exceeds the maximum retransmissionfrequency.

Meanwhile, the p-band recovery timer is activated after the failure forthe p-band is determined. If the p-band recovery is not completed untilthe timer expires, the terminal may determine the RLF for the servingbase station. The band recovery process is mainly applied to the p-band,but may also be applied to the common band or the s-band according tothe embodiment. The following four band recovery procedures may bepossible.

Case 1: gNB-triggered,

Case 2: UE-triggered,

Case 3: gNB/UE-triggered & UL-based recovery,

Case 4: gNB/UE-triggered & DL-based recovery

FIG. 11 is a diagram illustrating a band recovery process according toan embodiment of the present disclosure, FIG. 12 is a diagramillustrating a band recovery process according to an embodiment of thepresent disclosure, FIG. 13 is a diagram illustrating a band recoveryprocess according to an embodiment of the present disclosure, and FIG.14 is a diagram illustrating a band recovery process according to anembodiment of the present disclosure.

FIG. 11 illustrates flowcharts of operations of the base station (1stnode) and the terminal (2nd node) according to a method in which thebase station triggers a band recovery process. The base station mayreconfigure another band as a P-band based on the measurement report.

Referring to FIG. 11 , the base station may configure, to the terminal,a first band as a primary band for serving cell measurement in operation1110, and configure a second band that is not configured as a primaryband for serving cell measurement in operation 1120. In operation 1130,the base station may receive measurement report for the first bandand/or the second band from the terminal. In operation 1140, the basestation may determine whether to change the primary band with the secondband based on the measurement report received from the terminal inoperation 1130. Further, in operation 1150, the base station may performconfiguration to the terminal to change the primary band with the secondband as a new primary band according to the determination in operation1140.

Meanwhile, the terminal may receive configuration for the first band asa primary band from the base station for serving cell measurement inoperation 1160, and receive configuration for the second band that isnot configured as a primary band for serving cell measurement inoperation 1170. In operation 1180, the terminal may transmit themeasurement report for the first band and/or the second band to the basestation. Further, in operation 1190, the terminal may receive theconfiguration from the base station to change the primary band with thesecond band as a new primary band according to the determination of thebase station in operation 1140. The terminal changes the primary bandwith the second band as a new primary band according to theconfiguration of the base station, and may apply attributes andmeasurement operation applied to the previous primary band to the newprimary band.

FIG. 12 illustrates flowcharts of operations of the base station (1stnode) and the terminal (2nd node) according to a method in which theterminal triggers a band recovery process according to an embodiment ofthe present disclosure.

The terminal detecting low signal quality of the base station may informthe base station of a candidate band to which the terminal will move. Atthis time, the terminal may transmit, to the base station, informationon the candidate band to which the terminal will move through an ULresource allocated in advance. Further, the base station may reconfigurethe P-band based on the information received from the terminal.

Referring to FIG. 12 , the base station may configure a first band as aprimary band to the terminal for a purpose of serving cell measurementin operation 1210. Further, the base station may set an UL resource forproblem report on the primary band to the second band that is notconfigured as the primary band in operation 1215. The terminal maydetermine whether a validity condition based on a channel state of theprimary band (first band) is met, and determine whether a failure of theprimary band occurs. If the channel of the primary band does not meetthe validity condition, the terminal may transmit problem report thereonto the base station, and the base station may receive the report messagein operation 1220. At this time, the base station may receive report onthe second band in addition to the report on the primary band from theterminal. If the base station receives the problem report on the primaryband in operation 1220, the base station may determine whether to changethe primary band with the second band as a new primary band in operation1225. At this time, the base station may determine whether to determinethe second band as a new primary band by referring to at least one of aresult of measurement on the second band and signal quality of the firstband in which the problem occurs. Further, in operation 1230, the basestation may perform configuration to the terminal to change the primaryband with the second band as a new primary band according to thedetermination in operation 1225.

Meanwhile, the terminal may receive the configuration of the first bandas a primary band for the purpose of serving cell measurement from thebase station in operation 1240. Further, the terminal may receivesetting an UL resource for problem report on the primary band to thesecond band that is not configured as the primary band from the basestation in operation 1245. In operation 1250, the terminal may determinewhether a validity condition based on a channel state of the primaryband (first band) is met, and determine whether a failure of the primaryband occurs. Further, if the channel of the primary band does not meetthe validity condition, the terminal may transmit problem report thereonto the base station via the second band in operation 1255. In operation1260, the terminal may receive the configuration from the base stationto change the primary band with the second band as a new primary bandaccording to the determination of the base station in operation 1225.The terminal changes the primary band with the second band as a newprimary band according to the configuration of the base station, and mayapply attributes and measurement operation applied to the previousprimary band to the new primary band.

Referring to FIG. 13 , according to an embodiment of the presentdisclosure, the base station/terminal triggers the band recoveryprocess, and flowcharts of operations of the base station (1st node) andthe terminal (2nd node) according to an UL-based band recovery processare illustrated. Both the base station and the terminal detect lowsignal quality, and accordingly, the base station may reconfigure a newband as a P-band according to probing signal transmission of the basestation and signal transmission of the terminal in response theretobefore a certain timer expires.

The base station may configure a first band as a primary band to theterminal for a purpose of serving cell measurement in operation 1310.Further, the base station may set an SRS resource to the second andthird bands that are not configured as the primary band in operation1315. Further, the base station may set a resource for probing signaltransmission of the base station for the primary band (first band). Atthis time, the second band may be one or more bands in view of the basestation, and the third band may be at least one of a plurality of secondbands that is determined by the terminal. The terminal may determinewhether a validity condition based on a channel state of the primaryband (first band) is met, and determine whether a failure of the primaryband occurs. In operation 1320, the base station may determine whether avalidity condition based on a channel state of the first band is metbased on the SRS signal of the terminal, and determine whether a failureof the primary band occurs. Further, if a channel of the primary banddoes not meet the validity condition, in operation 1325, the basestation starts a first timer and may transmit a probing signal to theterminal via the second band until the first timer expires. When theprobing signal is transmitted, the base station starts a second timer,and in operation 1330, the base station may wait to receive a responsesignal until the second timer expires. In operation 1335, the basestation may determine whether to change the primary band with the thirdband as a new primary band based on the response signal of the terminalfor the probing signal transmitted via the second band. The responsesignal may be received via the third band. Further, the base station mayperform configuration to the terminal to change the primary band withthe third band as a new primary band according to the determination inoperation 1335.

Meanwhile, the terminal may receive the configuration of the first bandas a primary band for the purpose of serving cell measurement from thebase station in operation 1340. Further, the terminal may receive, fromthe base station, setting for an SRS resource of the terminal to thesecond and third bands that are not configured as the primary band inoperation 1345. Further, the terminal may receive, from the basestation, setting for a resource for probing signal transmission of thebase station for the primary band (first band). In operation 1350, theterminal may determine whether a validity condition based on a channelstate of the primary band (first band) is met, and determine whether afailure of the primary band occurs. Further, the terminal may transmitthe SRS signal to the base station if a failure of the primary bandoccurs. If a channel of the primary band does not meet the validitycondition, the terminal starts a third timer and may wait to receive aprobing signal of the base station via all the configured second bandsuntil the third timer expires. The third timer may be the same as thefirst timer. When the terminal receives the probing signal in operation1355, the terminal starts a fourth timer therefor, and in operation1360, the terminal may transmit a response signal to the base stationvia the third band. The fourth timer may be the same as the secondtimer. In operation 1365, the terminal may receive the configurationfrom the base station to change the primary band with the third band asa new primary band according to the determination of the base station inoperation 1335. The terminal changes the primary band with the thirdband as a new primary band according to the configuration of the basestation, and may apply attributes and measurement operation applied tothe previous primary band to the new primary band.

Referring to FIG. 14 , according to an embodiment of the presentdisclosure, the base station/terminal triggers a band recovery process,and flowcharts of operations of the base station (1st node) and theterminal (2nd node) according to a DL-based recovery method isillustrated. Both the base station and the terminal detect low signalquality, and accordingly, the base station may reconfigure a new band asa P-band according to a measurement report of the terminal before acertain timer expires.

The base station may configure a first band as a primary band to theterminal for a purpose of serving cell measurement in operation 1410.Further, the base station may set an RS resource of the base station toa second band and a third band that are not configured as a primary bandin operation 1415, and may set, to the terminal, a timer-basedmeasurement report for the set RS resource. At this time, the secondband may be one or more bands in view of the base station, and the thirdband may be at least one of a plurality of second bands that isdetermined by the terminal. The terminal may determine whether avalidity condition based on a channel state of the primary band (firstband) is met, and determine whether a failure of the primary bandoccurs. Further, in operation 1420, the base station may determinewhether a validity condition based on a channel state of the first bandis met based on the measurement report of the terminal, and determinewhether a failure of the primary band occurs. If a channel of theprimary band does not meet the validity condition, in operation 1425,the base station starts a first timer and a second timer and maytransmit a reference signal (RS) to the terminal via the second banduntil the first timer expires. In operation 1430, the base station maywait to receive the measurement report until the second timer expires.The measurement report may be received via the third band. In operation1435, the base station may determine whether to change the primary bandwith the third band as a new primary band based on the measurementreport of the terminal for the RS transmitted via the second band.Further, the base station may perform configuration to the terminal tochange the primary band with the third band as a new primary bandaccording to the determination in operation 1435.

Meanwhile, the terminal may receive the configuration of the first bandas a primary band for the purpose of serving cell measurement from thebase station in operation 1440. Further, the terminal may receive thesetting of the RS resource of the base station to the second band andthe third band that are not configured as a primary band in operation1445, and may receive the setting of the timer-based measurement reportfor the set RS resource. In operation 1450, the terminal may determinewhether a validity condition based on a channel state of the primaryband (first band) is met, and determine whether a failure of the primaryband occurs. Further, if the channel of the primary band does not meetthe validity condition, the terminal may start a third timer and afourth timer. The third timer is the same as the first timer, and thefourth timer may be the same as the second timer. In operation 1455, theterminal may receive the RS of the base station via all configuredsecond bands until the third timer expires. When receiving the RS, theterminal may transmit a measurement report thereon to the base stationvia the third band until the third timer expires in operation 1460 Inoperation 1465, the terminal may receive the configuration from the basestation to change the primary band with the third band as a new primaryband according to the determination in operation 1435. The terminalchanges the primary band with the third band as a new primary bandaccording to the configuration of the base station, and may applyattributes and measurement operation applied to the previous primaryband to the new primary band. Meanwhile, in determining signal qualityin a specific band, the following four options may be considered.

Option 1: P-band

Option 2: P-band and common band for initial access

Option 3: P-band and S-band(s)

Option 4: P-band, S-band(s) and common band for initial access

A band recovery operation basically is a process of measuring channelquality for a plurality of bands and switching a P-band with other bandaccording to a result of the measurement. In the process, the operationof measuring channel quality for each band and the band switch processmay be separated and the band switch process may be performed by one ofthe following methods.

-   -   a) The base station may configure a plurality of bands together        with indices thereof to the terminal by an RRC message, and then        indicate band activation or band deactivation by an MAC CE or L1        signal including a band index. The terminal may switch a band        indicated by the band index to the activated state or        deactivated state according to the indication of band activation        or deactivation.    -   b) The base station may configure a plurality of bands together        with indices thereof to the terminal by an RRC message, and then        indicate band switch by an MAC CE or L1 signal including two        band indices for a current band and a subject band. The terminal        may switch the band indicated by the current band index to the        deactivated state and switch the band indicated by the subject        band index to the activated state, according to the indication        of band switch.    -   c) The base station may configure two bands together with        indices thereof to the terminal by an RRC message while further        including an index for this configuration, and then indicate        band switch by an MAC CE or L1 signal together with the        configuration index. The terminal may switch, among two bands        designated in the configuration, the band that is currently in        the activated state to the deactivated state and switch the band        that is currently in the deactivated state to the activated        state, according to the indication of band switch.    -   d) The base station may configure m bands together with indices        thereof to the terminal by an RRC message, and then indicate        band switch by an MAC CE or L1 signal including a current band        index. The terminal may switch the band indicated by the current        band index to the deactivated state and switch a band indicated        by the next band index to the activated state in an order of        index, according to the indication of band switch.    -   e) The base station may configure m bands together with indices        thereof to the terminal by an RRC message while further        including an index for this configuration, and then indicate        band switch by an MAC CE or L1 signal including the        configuration index and the current band index. The terminal may        switch the band indicated by the current band index to the        deactivated state and switch a band indicated by the next band        index to the activated state in an order of index, according to        the indication of band switch.    -   f) The base station may configure m bands together with indices        thereof to the terminal by an RRC message, set priority of the        bands, and indicate band switch by an MAC CE or L1 signal        including a current band index. The terminal may switch the band        indicated by the current band index to the deactivated state and        switch a band indicated by the next band index to the activated        state in an order of priority, according to the indication of        band switch.    -   g) The base station may configure m bands together with indices        thereof to the terminal by an RRC message and set priority of        the bands while further including an index for this        configuration, and then indicate band switch by an MAC CE or L1        signal including the configuration index and the current band        index. The terminal may switch the band indicated by the current        band index to the deactivated state and switch a band indicated        by the next band index to the activated state in an order of        priority, according to the indication of band switch.

In the band switch process of a) to g), a retain time of the switchedband may be valid by meeting one of conditions of 1) until a nextindication to switch is issued, 2) after a predetermined time k (e.g.,symbol, slot, subframe, frame, or the like), and 3) after apredetermined time k (e.g., symbol, slot, subframe, frame, or the like)set by the base station by the RRC message. If the retain time expires,the terminal may return to the band state before the switching.

In the band switch process of a) to g), the deactivation may beperformed by a timer without a separate indication. For example, whenthe terminal monitors a downlink control channel of a specific band, ifa signal from the base station is not received by the terminal via theband until a certain timer expires, the terminal may deactivate theband.

RRM Measurement

FIG. 15 is a diagram illustrating a monitoring bandwidth of a terminalfor a serving base station and a neighboring base station according toan embodiment of the present disclosure, FIG. 16 is a diagramillustrating a monitoring bandwidth of a terminal for a serving basestation and a neighboring base station according to an embodiment of thepresent disclosure, FIG. 17 is a diagram illustrating a monitoringbandwidth of a terminal for a serving base station and a neighboringbase station according to an embodiment of the present disclosure, andFIG. 18 is a diagram illustrating a monitoring bandwidth of a terminalfor a serving base station and a neighboring base station according toan embodiment of the present disclosure.

The terminal needs to always monitor a DL control channel even whenreceiving a data service of small capacity. Therefore, if a monitoringbandwidth is large, power consumption may be large even at the time ofdata service of small capacity. The terminal may receive a setting of amonitoring resource having a small size from the serving base stationfor purposes of reduction in power consumption and the like and receivethe DL control channel through the resource. In an embodiment of thepresent disclosure, a band scheduling method for, such as operation isdescribed. However, even when the terminal performs an operation ofreception from the serving base station via a limited band (BW), in thecase of connected mode terminal, the entire band may need to bemonitored in order to perform a radio resource management (RRM)measurement operation of a neighboring cell. Meanwhile, the measurementfor the serving base station may be performed by at least one of thefollowing methods.

Option A (L1):

Option A-1: control sub-band embeds RS location

Option A-2: control sub-band indicates another control sub-band in thesame or upcoming subframe

Option A-3: control sub-band indicates additional RS location in thesame or upcoming subframe

Option B (RRC):

Option B-1: control sub-band and RS location is indicated separately inRRC message

Option B-2: control sub-band and RS location is indicated together inRRC message

Referring to FIG. 15 , a terminal 1510 may receive a control channelfrom a serving base station (gNB1) 1520 via a partial band 1530.Further, the terminal 1510 may be set to monitor a wide band 1540 forRRM measurement for a neighboring base station (gNB2) 1525, that is, inorder to receive a synchronization signal (sync, PBCH) 1555 and areference signal (RS) 1550. This may result in high power consumption ofthe terminal 1510.

Referring to FIG. 16 , when the same bands 1610 and 1620 are allocatedto the terminal 1510 for control channel monitoring from the servingbase station 1520 and RRM measurement 1630 from the neighboring basestation 1525, several μs of switching delay may occur. For thisoperation, the serving base station 1520 may configure a dedicated RRMband 1620 for performing the RRM measurement for the neighboring basestation 1525 to the terminal 1510. An active band 1610 operated in theserving base station 1520 may include the dedicated RRM band 1620.Further, the terminal 1510 may perform the RRM measurement while notfollowing measurement gap configuration, if not changing a centerfrequency.

Referring to FIG. 17 , when bands 1710 and 1720 that do not overlap eachother are allocated to the terminal 1510 for control channel monitoringfrom the serving base station 1520 and RRM measurement 1730 from theneighboring base station 1525, hundreds of μs of switching delay mayoccur. This shows that a subframe operated in a unit of 1 ms needs toconsider delay of 1 ms in the process. For this operation, the servingbase station 1520 may configure a dedicated RRM band 1720 for performingthe RRM measurement for the neighboring base station 1525 to theterminal 1510. If the active band operated in the serving base station1520 may not include the dedicated RRM band 1720, the terminal mayperform measurement according to measurement gap configuration.

Referring to FIG. 18 , when bands 1810 and 1820 partially overlappingeach other are each allocated to the terminal 1510 for control channelmonitoring from the serving base station 1520 and RRM measurements 1830and 1835 from the neighboring base station 1525, several to tens of μsof switching delay may occur. For this operation, the serving basestation 1520 may configure to the terminal 1510 a dedicated RRM band forperforming the RRM measurement for the neighboring base station 1525 anda reference band 1820 for synchronization. The terminal 1510 may includethe reference band 1820 in the active band 1810 operated in the servingbase station 1520, but if the center frequency needs to be changed, mayfirst performing synchronization for the neighboring base station 1525according to the measurement gap configuration. The terminal 1510 mayinclude the dedicated band 1820 in the active band 1810 operated in theserving base station 1520, but if the center frequency is not changed,may measure an RS of the neighboring base station in the current activeband regardless of the measurement gap configuration.

According to an embodiment of the present disclosure, the base stationmay configure a separate band to the terminal for RRM measurement forthe neighboring base station. The terminal may receive configuration ofa band for measurement from the serving base station or neighboring basestation according to at least one the following methods.

Option A: The serving base station may configure a band for measurementto the terminal connected to the serving base station based oninformation received from the neighboring base station. The serving basestation may inform the terminal of an ID (e.g., a cell ID, a TRP(TxRxPoint) ID, or the like) of a measurement subject together withinformation on a location/size of the band for measurement.Configuration of a sub-band and a band of the serving base station maybe different from that of the neighboring base station, but the servingbase station may control the terminal to enter a region in which asignal of the neighboring base station may be received as far aspossible. The terminal succeeds in receiving a synchronization signaland a PBCH of the neighboring base station or receives an RRC message ofthe serving base station, thereby acquiring numerology information usedby the neighboring base station and re-calculating an accurate RSlocation of the neighboring base station based on the acquirednumerology information. The terminal may perform measurement at thechecked RS location.

Option B: The terminal succeeds in receiving a synchronization signaland a PBCH of the neighboring base station to determine an RS locationaccording to BW capability of the terminal included in SI and performsmeasurement in the corresponding RS location.

Option C: The terminal performs a process of initial access to theneighboring base station, reports capability information of the terminalto the neighboring base station, and receives a response message of theneighboring base station to perform measurement in an RS locationincluded in the message.

According to an embodiment of the present disclosure, the base stationmay configure a band to the terminal by interworking with a band forscheduling for RRM measurement for the neighboring base station. Thebase station may inform the terminal of a band index together withresource setting for one or more CSI-RSs in RRM measurementconfiguration. 1) The band index also has the numerology information,thus numerology for the CSI-RS resource may also follow the numerologyinformation interworking with the indicated band. Alternatively, 2) whennumerology information is included in CSI-RS resource setting, and thenumerology information included in the CSI-RS resource setting conflictswith the numerology information of the band index, the terminal mayfollow the numerology information included in the CSI-RS resourcesetting for the RRM measurement.

Meanwhile, the serving base station may separately or integrally setresource areas for receiving a control channel of the serving basestation and an RS of the neighboring base station to the terminal. Inthe case in which the resource areas are integrated and set as oneresource area, the terminal may perform a control channel receptionoperation and a neighboring base station measurement operation by a timedivision multiplexing (TDM) scheme or frequency division multiplexing(FDM) scheme, separately. In the case of TDM, the serving base stationmay allocate a measurement gap to the terminal. The base station may beoperated according to at least one of the followings: a) performingconfiguration so that the terminal necessarily receives a signal of theneighboring base station at a specific point in time, b) performingconfiguration so that the terminal merely has an opportunity theterminal to receive a signal of the neighboring base station at aspecific point in time and determines whether to receive the signal ofthe neighboring base station based on an operation condition for theserving base station of the terminal, and c) performing configuration sothat the terminal merely has an opportunity the terminal to receive asignal of the neighboring base station at a specific point in time andreceives the signal of the neighboring base station only when there isno operation indicated for the serving base station.

In performing an L3 filtering operation, the terminal may reflect only ameasurement result in a RRM BW as an input value of an L3 filter.Alternatively, the terminal may separate each measurement result foreach BW when performing measurement both in a RRM BW and an active bandBW. Further, the terminal may abandon the existing L3 filtering and makea new start if an RRM BW is reset, or an averaging value for the RRM BWis not received from L1 within a predetermined time.

As the RRM BW, one or a plurality of BWs may be configured to theterminal according to determination of the base station, and if theplurality of RRM BWs are set, the terminal may be operated by selectingan RRM BW in which retuning latency is shortest according to arelationship with a band being operated. Alternatively, the terminal maybe operated by preferentially selecting an RRM BW including an SS amongthe plurality of RRM BWs. Alternatively, the terminal may be operated byselecting an RRM BW based on priority for the plurality of RRM BWs thatis set by the base station and a retuning latency constraint. Forexample, the terminal may select an RRM BW with highest priority amongRRM BWs in which retuning latency is shorter than time k (e.g., symbol,slot, subframe, frame, or the like) for switching to the RRM BW in theactivated band or primary band.

Measurement Gap Configuration and Measurement Operation at the Time ofRRM BW Setting and Simultaneous Operation with Part of BW for ConnectedMode

The base station may set a frequency resource for performing RRMmeasurement to the terminal, and this will hereinafter be referred to asRRM BW. Further, the base station may configure one or more bands to theterminal for scheduling, or the like. If the RRM BW and a BW allocatedto the band may be switched to each other without RF retuning, theterminal may perform the RRM measurement during signal transmission andreception with the base station. However, if the terminal may switch theRRM BW and the BW of the band only if the RF retuning is performed, theRRM measurement may be performed according to measurement gapconfiguration of the base station. A latency by the retuning may bedetermined by various factors, such as whether a center frequency of theoperating RF band is changed, whether numerology needs to be changed formeasurement, and the like.

Meanwhile, since the terminal may receive configuration of one or morebands, whether to apply the measurement gap may be optionally determineddepending on a relationship of the RRM BW for the current P-band, activeband, or a band being used for data transmission and reception. Forexample, if RF retuning for switching to the RRM BW is performed for oneor more bands in which the terminal is currently operated among theplurality of bands or an RF retuning latency time is longer than apredetermined latency, the configured measurement gap may be activated.For example, if the RF retuning for switching to the RRM BW is performedfor one or more bands that are activated or being used before time k(e.g., slot, symbol, subframe, or the like) of a gap start pointaccording to the measurement gap configuration, the terminal may preparethe RRM measurement in the measurement gap. In the measurement gap, theterminal may complete the RF retuning in advance to perform measurementfor a measurement resource set in the RRM BW. For example, if the RFretuning for switching to the RRM BW is performed for one or more bandsthat are activated or being used at the gap start point according to themeasurement gap configuration, and it is determined that the measurementgap does not reach an end point in time within a time that is acombination of RF retuning latency and a minimum measurement time, theterminal may perform the RRM measurement in the measurement gap. In themeasurement gap, the terminal may complete the RF retuning in advance toperform measurement for a measurement resource set in the RRM BW. If theRF retuning is performed and it is determined that the measurement gapreaches the end point in time within the time that is a combination ofthe RF latency and the minimum measurement time, the terminal does notperform the RRM measurement in the measurement gap.

If measurement report is not performed within a set period, the basestation may make inquiries about a cause thereof, and the terminal mayreport an index value including information on the cause in response tothe request of the base station. Alternatively, the terminal maytransmit a measurement gap reconfiguration request to the base station,and the base station may make determination based on a cause of themeasurement gap reconfiguration request transmitted from the terminaland terminal capability information to reconfigure the measurement gap.

Meanwhile, depending on the relationship of monitoring bandwidth s withthe serving base station and the neighboring base station, thefollowings may be further considered.

Case A: Aligned Across Cells

Measurement gap for intra-carrier is not configured

Including the minimum BW for sync/PBCH/(paging)

Case B: Non-Aligned Across Cells (Measurement Gap for Intra-Carrier isConfigured)

Option 1: maintaining the common BW in the partial BW across cells

Option 2: flexible configuration for the partial BW

Case C: Partially Overlapped Across Cells

Measurement gap for specific target is configured

FIG. 19 is a diagram illustrating a flexible BW system desired in a 5Gcommunication system according to an embodiment of the presentdisclosure.

Referring to FIG. 19 , the flexible BW system is configured by three BWsincluding an access BW, an idle mode BW, and a connected mode BW, andswitching between them.

The access BW means a minimum BW used by the terminal for performing aninitial access process, such as cell selection, SI acquirement, randomaccess, and the like. The access BW basically may be determined inadvance according to a carrier frequency. However, in a scenario ofaccessing by controlling another base station in different radio accesstechnology (RAT) or the same RAT by an anchor base station, the terminalmay receive access BW information or information for acquiring access BWthrough the anchor base station. The access BW is configured of asub-band and a band exemplified in an embodiment of the presentdisclosure, and the base station may configure the access BW to theterminal through SI or RRC message. A location of a basic downlinkcontrol channel may be set by the number of control sub-bands andsymbols. Further, a location of a basic downlink data channel may be setby a band corresponding to a control sub-band. As the basic downlinkdata channel, a basic DL-SCH (downlink shared channel) of an L2 layermay be set. Further, the base station may set a reference frequencylocation (e.g., carrier center frequency, or the like) for calculatingthe BW information together to the terminal.

The idle mode BW means a BW set for performing a process, such asadditional SI acquirement, paging, random access, and the like, by theterminal. As suggested in an embodiment of the present disclosure, theidle mode BW may be the same as the access BW, but a BW different fromthe access BE may be set as the idle mode BW to sufficiently improveutilization of broadband. As a setting method thereof, SI is generallyused, but in some cases, an RRC message may be used for the setting. Forexample, the terminal may receive setting of the idle mode BW in advancefrom the base station in a connected state, or may acquire informationfor determining the idle mode BW (e.g., the number of bands of the basestation, band/sub-band configuration, the number of common signalingresources, and the like).

The connected mode BW means a BW set to the terminal for configurationof the control/data channel. The control sub-band and band informationmay be set through an RRC message. In addition to the basic downlinkcontrol/data channel and the basic DL-SCH determined by the access BWacquirement, additional downlink control/data channel and DL-SCH may beset. When paging indication is received or UL data is generated, theterminal may receive setting for the connected mode BW through therandom access process. The terminal may be operated according to thecontrol/data channel set to the connected mode BW by switching to theconnected mode.

Meanwhile, a synchronization signal (SS) and a CSI-RS may be consideredfor the RRM measurement. The synchronization signal is transmitted andreceived in the access BW, and if cell-specific, the CSI-RS may betransmitted and received in the idle mode BW or the connected mode BW,and if UE-specific, the CSI-RS may be transmitted in the connected modeBW. The base station may operate the BW according to various situationsfor each terminal.

For example, according to situation 1, the terminal may performmeasurement by setting a synchronization signal in the access BW as areference signal for the RRM measurement. Further, the terminal may beoperated by assuming that the idle mode BW is the same as the access BWif there is no separate setting for the idle mode BW. For example, theidle mode operation, such as cell (re-)selection and the like may beperformed according to a result of measurement for the SS.

According to situation 2, the terminal may receive setting of an idlemode BW that includes the access BW and is large than the access BW fromthe base station through the SI. Further, the terminal may receivesetting of a cell-specific CSI-RS for the idle mode BW. The terminal mayperform measurement for the cell-specific CSI-RS according tomeasurement configuration, and perform the idle mode operation, such ascell (re-)selection based on a result thereof. The terminal measures anSS for a base station that does not use the cell-specific CSI-RS, thusmay be operated by reflecting an offset value for correcting an errorbetween performance indices. According to some measurementconfiguration, the terminal may be operated based on a representativevalue for the SS and cell-specific CSI-RS measurement result.

According to situation 3, the terminal may receive setting of an idlemode BW that does not include the access BW from the base stationthrough the SI. Further, the terminal may receive setting of acell-specific CSI-RS for the idle mode BW. The terminal may performmeasurement for the cell-specific CSI-RS according to measurementconfiguration, and perform the idle mode operation, such as cell(re-)selection based on a result thereof. The terminal measures an SSfor a base station that does not use the cell-specific CSI-RS, thus maybe operated by reflecting an offset value for correcting an errorbetween performance indices. At this time, the neighboring base stationtransmits an SS in the access BW, and the terminal monitors an idle modeBW different from the access BW set by the serving base station, thusthe serving base station may configure a measurement gap or set ameasurement resource so that an access BW of the neighboring basestation is monitored by RF retuning to the terminal. The terminal maymeasure the SS of the neighboring base station in the configuredmeasurement gap or the set measurement resource and reflect the offsetvalue for error correction, thereby performing the idle mode operation,such as cell (re-)selection, and the like.

According to situation 4, the terminal may receive setting of aconnected mode BW that includes the access BW or idle mode BW and is thesame as or large than the access BW or idle mode BW from the basestation through the RRC message. Further, the terminal may receivesetting of a cell/UE-specific CSI-RS for the connected mode BW. Theterminal may perform measurement for the cell/UE-specific CSI-RSaccording to measurement configuration, and perform the connected modeoperation, such as RRM measurement and report, and the like based on aresult thereof. The terminal may perform measurement in order ofpriority, that is, in order of an UE-specific CSI-RS, a cell-specificCSI-RS, and an SS. The terminal may report the measurement results foreach kind of measured RS to the base station.

According to situation 5, the terminal may receive setting of aconnected mode BW that does not include the access BW or idle mode BW orpartially overlaps with the access BW or idle mode BW from the basestation through the RRC message. Further, the terminal may receivesetting of a cell/UE-specific CSI-RS for the connected mode BW. Theterminal may perform measurement for the cell/UE-specific CSI-RSaccording to measurement configuration, and perform the connected modeoperation, such as RRM measurement and report, and the like based on aresult thereof. The terminal may report the measurement results for eachkind of measured RS to the base station. The terminal measures an SS fora base station that does not use the cell/UE-specific CSI-RS, thus maybe operated by reflecting an offset value for correcting an errorbetween performance indices. At this time, the neighboring base stationtransmits an SS in the access BW, and the terminal monitors a connectedmode BW different from the access/idle BW set by the serving basestation, thus the serving base station may configure a measurement gapor set a measurement resource so that an access/idle BW of theneighboring base station is monitored by RF retuning to the terminal.The terminal may measure the SS of the neighboring base station in theconfigured measurement gap or the set measurement resource and reflectthe offset value for error correction, thereby performing the connectedmode operation, such as RRM measurement and report, and the like.

FIG. 20 is a diagram illustrating a configuration of a terminalaccording to an embodiment of the present disclosure.

Referring to FIG. 20 , the terminal may include a transceiver 2010performing signal transmission and reception with a network entity, suchas other terminal and base station, and a controller 2020 controllingall operations of the terminal. In an embodiment of the presentdisclosure, all operations for supporting the synchronization describedabove may be understood as being performed by the controller 2020.However, the controller 2020 and the transceiver 2010 are notnecessarily implemented as separate apparatuses, but may be implementedas one component in a form like a single chip. Further, the controller2020 and the transceiver 2010 may be electrically connected to eachother. The transceiver 2010 may include a transmitter 2013 and areceiver 2015. Further, the terminal may further include a memory 2030.

The controller 2020 of the terminal controls the terminal to perform anyone of the operations in the embodiments described above. For example,the controller 2020 of the terminal may receive, from a base station, afirst message including configuration information of at least one band,receive, from the base station, a second message for activating a bandamong the at least one band, and activate the band according to thesecond message.

The controller 2020 may include a system decision unit 2023, a BWcontroller 2025, and a measurement unit 2027. The system decision unit2023 may control the operation of the terminal according to theconfiguration of the base station described above, and the BW controller2025 may determine and control an operating bandwidth of the terminal.The measurement unit 2027 may measure a reference signal from the basestation and store the measurement result in the memory 2030. Meanwhile,the system decision unit 2023, the BW controller 2025, and themeasurement unit 2027 are not necessarily implemented as separatemodules, but may be implemented as one component in a form like a singlechip.

Further, the transceiver 2010 of the terminal may transmit and receive asignal according to any one of the operations in the embodimentsdescribed above.

Further, the controller 2020 may be, for example, a circuit, anapplication-specific circuit, or at least one processor. Further, theoperations of the terminal may be implemented by providing a memorydevice (memory 2030) storing a corresponding program code in anycomponent in the base station. For example, the controller 2020 mayexecute the operations described above by reading and executing theprogram code stored in the memory device by a processor, a centralprocessing unit (CPU), or the like.

It should be noted that the configuration diagram of the terminalillustrated in FIG. 20 , the exemplified diagram of the control/datasignal transmission method, the exemplified diagram of the operatingprocess of the terminal, and the configuration diagrams of the terminalapparatus are not intended to limit the scope of rights of the presentdisclosure. For example, all components, entities, or operations of anoperation illustrated in FIG. 20 are not to be interpreted as being anessential constituent element for implementing the present disclosure,and may be implemented without departing from the gist of the presentdisclosure.

FIG. 21 is a diagram illustrating a configuration of a base stationaccording to an embodiment of the present disclosure.

Referring to FIG. 21 , the base station may include a transceiver 2110performing signal transmission and reception with other network entity,such as a terminal and an MME, and a controller 2120 controlling alloperations of the base station. In an embodiment of the presentdisclosure, all operations for supporting the synchronization describedabove may be understood as being performed by the controller 2120.However, the controller 2120 and the transceiver 2110 are notnecessarily implemented as separate apparatuses, but may be implementedas one component in a form like a single chip. Further, the controller2120 and the transceiver 2110 may be electrically connected to eachother. The transceiver 2110 may include a transmitter 2113 and areceiver 2115. Further, the base station may further include a memory2130.

The controller 2120 of the base station controls the base station toperform any one of the operations in the embodiments described above.For example, the controller 2120 of the base station may transmit, to aterminal, a first message including configuration information of atleast one band, and transmit, to the terminal, a second message foractivating a band among the at least one band.

Further, the transceiver 2110 of the base station may transmit andreceive a signal according to any one of the operations in theembodiments described above.

Further, the controller 2110 may be, for example, a circuit, anapplication-specific circuit, or at least one processor. Further, theoperations of the base station may be implemented by providing a memorydevice (memory 2130) storing a corresponding program code in anycomponent in the base station. For example, the controller 2110 mayexecute the operations described above by reading and executing theprogram code stored in the memory device by a processor, a CPU, or thelike.

Further, the operations of the base station or the terminal may beimplemented by providing a memory device (memory 2130) storing acorresponding program code in any component in the base station orterminal apparatus. For example, the controller 2020 or 2120 of the basestation or the terminal may execute the operations described above byreading and executing the program code stored in the memory device 2030or 2130 by a processor or a CPU.

Various components, modules, and the like, of the entities described inthe present specification, the base station or the terminal apparatusmay be operated by using a hardware circuit, for example, acomplementary metal oxide semiconductor-based logic circuit, firmware,software and/or hardware, or a combination of firmware and/or softwareinserted in a machine-readable medium. As an example, various electricstructures and methods may be implemented using transistors, logicgates, and electric circuits, such as an application specific integratedcircuit (ASIC).

While the present disclosure has been described in connection with thedetailed embodiments thereof, various modifications can be made withoutdeparting from the scope of the present disclosure. Therefore, the scopeof the present disclosure should be not construed as being limited tothe described embodiments but be defined by the appended claims as wellas equivalents thereto.

The embodiments of the present disclosure disclosed in the presentspecification and the accompanying drawings have been provided merely asspecific examples in order to assist in understanding the descriptionand do not limit the scope of the present disclosure. It is obvious tothose skilled in the art to which the present disclosure pertains thatvarious modifications may be made without departing from the scope ofthe present disclosure, in addition to the embodiments disclosed herein.

Embodiments have been described in the detailed description and theaccompanying drawings. Herein, although specific terms have been used,these are merely used for the purpose of easily describing the presentdisclosure but not used for limiting the scope of the presentdisclosure. It is obvious to those skilled in the art to which thepresent disclosure pertains that various modifications may be madewithout departing from the scope of the present disclosure, in additionto the embodiments disclosed herein.

While the present disclosure has been shown and described with referenceto various embodiments thereof, it will be understood by those skilledin the art that various changes in form and details may be made thereinwithout departing from the spirit and scope of the present disclosure asdefined by the appended claims and their equivalents.

What is claimed is:
 1. A method performed by a terminal in a wireless communication system, the method comprising: receiving, from a base station, a radio resource control (RRC) message including a configuration of at least one band and a configuration of a primary band for the terminal, wherein the configuration of the at least one band includes at least one of a subcarrier spacing, a cyclic prefix, or information on frequency domain location and bandwidth for the at least one band; monitoring, from the base station, a control channel on the primary band; and receiving, from the base station, downlink control information indicating an active band from the at least one band on the control channel.
 2. The method of claim 1, further comprising: switching from the active band to a recovery band, in case that a predetermined timer expires.
 3. The method of claim 1, wherein the receiving the downlink control information comprises: identifying the primary band based on the configuration of the primary band; receiving, from the base station, the downlink control information indicating the active band from the at least one band; and switching from the primary band to the active band according to the downlink control information.
 4. The method of claim 1, further comprising: performing communication with the base station based on the active band.
 5. The method of claim 1, wherein the configuration of at least one band further includes at least one band identifier corresponding to the at least one band, and wherein the at least one band comprises at least one of at least one downlink band or at least one uplink band.
 6. A method performed by a base station in a wireless communication system, the method comprising: transmitting, to a terminal, a radio resource control (RRC) message including a configuration of at least one band and a configuration of a primary band for the terminal, wherein the configuration of the at least one band includes at least one of a subcarrier spacing, a cyclic prefix, or information on frequency domain location and bandwidth for the at least one band; and transmitting, to the terminal, downlink control information indicating an active band from the at least one band based on a control channel on the primary band.
 7. The method of claim 6, wherein the active band is switched to a recovery band, in case that a predetermined timer expires.
 8. The method of claim 6, wherein a-the primary band is identified based on the configuration of the primary band, and the primary band is switched to the active band according to the downlink control information.
 9. The method of claim 6, further comprising: performing communication with the terminal based on the active band.
 10. The method of claim 6, wherein the configuration of at least one band further includes at least one band identifier corresponding to the at least one band, and wherein the at least one band comprises at least one of at least one downlink band or at least one uplink band.
 11. A terminal in a wireless communication system, the terminal comprising: a transceiver; and a controller coupled with the transceiver and configured to: receive, from a base station, a radio resource control (RRC) message including a configuration of at least one band and a configuration of a primary band for the terminal, wherein the configuration of the at least one band includes at least one of a subcarrier spacing, a cyclic prefix, or information on frequency domain location and bandwidth for the at least one band, monitor, from the base station, a control channel on the primary band, and receive, from the base station, downlink control information indicating an active band from the at least one band based on the control channel.
 12. The terminal of claim 11, wherein the controller is further configured to: switch from the active band to a recovery band, in case that a predetermined timer expires.
 13. The terminal of claim 11, wherein the controller is further configured to: identify the primary band based on the configuration of the primary band, receive, from the base station, the downlink control information indicating the active band from the at least one band, and switch from the primary band to the active band according to the downlink control information.
 14. The terminal of claim 11, wherein the controller is further configured to: perform communication with the base station based on the active band.
 15. The terminal of claim 11, wherein the configuration of at least one band further includes at least one band identifier corresponding to the at least one band, and wherein the at least one band comprises at least one of at least one downlink band or at least one uplink band.
 16. A base station in a wireless communication system, the base station comprising: a transceiver; and a controller coupled with the transceiver and configured to: transmit, to a terminal, a radio resource control (RRC) message including a configuration of at least one band and a configuration of a primary band for the terminal, wherein the configuration of the at least one band includes at least one of a subcarrier spacing, a cyclic prefix, or information on frequency domain location and bandwidth for the at least one band, and transmit, to the terminal, downlink control information indicating an active band from the at least one band based on a control channel on the primary band.
 17. The base station of claim 16, wherein the active band is switched to a recovery band, in case that a predetermined timer expires.
 18. The base station of claim 16, wherein the primary band is identified based on the configuration of the primary band, and the primary band is switched to the active band according to the downlink control information.
 19. The base station of claim 16, wherein the controller is further configured to: perform communication with the terminal based on the active band.
 20. The base station of claim 16, wherein the configuration of at least one band further includes at least one band identifier corresponding to the at least one band, and wherein the at least one band comprises at least one of at least one downlink band or at least one uplink band. 